Database Normalization

Normalization process is the establishment of the database structure so that most of the ambiguity can be removed. Normalization stage, starting from the most mild (1NF) to most stringent (5NF) usually only reach the level of 3NF or BCNF because already sufficient to generate the table-a table of good quality.

Why do normalization?
1. Optimizing table structures
2. Increase speed
3. The income data is the same
4. More efficient of storage media
5. Reduce redundancy
6. Avoid anomalies (insertion anomalies, deletion anomalies, update anomalies).
7. Improved data integrity

A table saying good (efficient) or if normal meet 3 criteria:
1. If there is decomposition (decomposition) table, it must be guaranteed safe decomposition (Lossless-Join Decomposition). That is, after the table is described for a new table-table, the table-table can  generate a new table with the same exact.
2. Maintain dependence on the functional changes in data (Dependency preservation).
3. Does not violate Boyce-Code Normal Form (BCNF)

If the three criteria (BCNF) can not be met, then at least the table does not violate the Normal Form of the third stage (3rd Normal Form / 3NF).

Functional Dependency

Functional Dependency attributes describe the relationship in a relationship. An attribute said functionally dependant on the other, if we use the value attribute to determine the value of the other attributes.

• The symbols is used to represent the functional dependency is →

→ read determine the functional

• notation: A → B

A and B are attributes of a table. A means of determining the functional B or B depends on A, if and only if there are 2 rows of data with the same value of A, then B is also the same value

• notation: A x→B

It is the opposite of the previous notation.

Example:

Functional Dependency:
1. NRP → Nama
2. Mata_Kuliah, NRP → Nilai
Non Functional Dependency:
1. Mata_Kuliah → NRP
2. NRP → Nilai

Functional Dependency of the table nilai

– Nrp → Nama

Because for each value Nrp the same, then the value of the same name

– (Mata_kuliah, NRP) → Nilai

Because the value of attributes depending on the NRP and Mata_kuliah together. In another sense Mata_kuliah for the NRP and the same, they also rated the same, because Mata_kuliah and the NRP is a key (is unique).
- Mata_kuliah x→ NRP
- NRP x→ Nilai

FIRST NORMAL FORM – 1NF

A table on the form said to be normal if I did not reside in the unnormalized form of a table, where there is a kind of field multiplication and field that allows a null (empty)

What is not the 1NF:
• Attribute values, many (Multivalue attributes).
• Attribute a composite or a combination of both.
So:
• Price is the domain attribute must be atomic rates
• Ex Student Data as follows:

Or

Tables above does not meet 1NF. So decomposition can be:
- Student Table:

- Hobbies Table:

Another example:

SECOND NORMAL FORM – 2NF

Normal form 2NF met in a table if it meets the form of 1NF, and all the attributes than the primary key, have a full Functional Dependency on primary key. A table does not meet 2NF, if there are attributes that Functional Dependency are only partial (only depending on the part of the primary key). If there are attributes that have no dependence on the primary key, then the attributes must be moved or removed. Y is full if it is said to delete anà• functional dependence X attribute A from X means that Y is no longer dependent functional. Y said if deleting a partial attribute A from X means that Y is functionally dependent.à• functional dependence X. The scheme in the form of the relation R 2NF if every non-primary key attribute A Î R depend on the full primary key functional R.

The following table meet 1NF, but not 2NF

Does not meet 2NF, because (NIM, KodeMk) is regarded as the primary key:
(NIM, KodeMk) → NamaMhs
(NIM, KodeMk) → Alamat
(NIM, KodeMk) → Matakuliah
(NIM, KodeMk) → sks
(NIM, KodeMk) → NilaiHuruf

Table needs to be some table decomposition eligible 2NF. So dependency functional as follows:
1. (NIM, KodeMk) → NilaiHuruf  (fd1)

2. NIM → {NamaMhs, Alamat}    (fd2)

3. KodeMk → {Matakuliah, Sks} (fd3)
So that:

1. fd1 (NIM, KodeMk, NilaiHuruf) → Nilai Table

2. fd2 (NIM, NamaMhs, Alamat) → Mahasiswa Table
3. fd3 (KodeMk, Matakuliah, SKS) → MataKuliah Table

Another example:

Third NORMAL FORM – 3NF

Normal form 3NF fulfilled if the form meets 2NF, and if there are no non-primary key attribute that has a dependence on non-primary key attributes of the other (transitive dependencies). Table following students eligible 2NF, but not 3NF.

Because there are non-primary key attribute (Kota and Provinsi), which has a dependence on non-primary key attributes of the other (KodePos):
KodePos → (Kota and Provinsi)
So that the table should be decomposition to :
- Mahasiswa (NIM, NamaMhs, Jalan, KodePos)
- KodePos (KodePos, Provinsi, Kota)

Another example:

Boyce-CODD NORMAL FORM (BCNF)

Boyce-Codd Normal Form constraint has a stronger form of the Normal third. To be BNCF, relations must be in the form of 1NF and forced each of the attributes depends on the function in the super key attributes. In the example below there is a relationship seminar, is the Primary Key NPM + Seminar.

Students may take one or two seminars. Each seminar requires 2 each of the students and led by one of the 2 seminar. Each leader can only take one seminar course. NPM in this example and show a Seminar Counsellor.

Relations Seminar is a form of Third Normal, but not BCNF because Code Seminar is still dependent on the function Counsellor, if any Counsellor can only teach a seminar. Seminar depend on one key attribute is not as super key. But relations Seminar should be parsed into two namely:

NORMAL FORM fourth and fifth(4NF adn 5Nf)

• Relations in fourth normal form (NF 4) if the relation in BCNF and dependency not contain many values. To remove the dependency of many values from a relation, we divide the relationship into two new relations. Each relation contains two attributes that have a lot of relationship value.

• Relations in fifth normal form (5NF) deal with the property called the join without any loss of information (lossless join). Fifth normal form (also called the 5 NF PJNF (projection join normal form). The case is very rare and appear difficult to detect in practice.

WHAT WE CAN LEARN ?

• 1NF:
- Omission multivalue attribute.
- Atomic domain.
• 2NF:
– All attribute than the primary key must have the functional dependency of whole (not partial) to the primary key.
• 3NF:
– No non-attribute primary key attribute to have the dependency of the non-primary key other.

DEFINITION
Structured approach to the design starting from early 1970. Structured approach, complete with tools and needed techniques in the development of the system, so that the final results of the system will be developed in a system with well defined structure and clear.

Through structured, complex problems can be solved in the organization and results of the system will easy to maintain, flexible, more satisfied users, have any documentation of good, timely, according to the budget cost of development, can improve productivity and quality will be better (free error).

DFD is a logical data model or process that is made to describe the origin of the data and the destination where the data out of the system, where data is stored, the process that produces the data and the interaction between the data stored and the process is imposed on data.

DFD are often used to describe a system that already exists or the new system will be developed logically without considering the physical environment where the data flows, or where data are stored and the user is easy to understand to understand the field of computer systems that will be done.

DFD is a tool that system design-oriented data flow with the concept of decomposition can be used for the delineation and analysis of system design that is easily communicated to the system by the professional user and the program.

Context Diagram

Context diagram has characteristics as follows:

• Consists of a process and describe the scope of a system
• It is the highest level of the DFD that describes the entire system to the input of the system and output
• The system is limited by Boundary (depicted by broken lines)
• No storage
• How to make it ? :
  1. Specify the name of the system.
  2. Determine the limits of the system.
  3. Specify the terminator are present in the system.
  4. Define what is received / given terminator from / to the system.
  5. Draw context diagram.

Zero Diagram

• Describe the process of the DFD
• Provide views on the overall system in which, showing the main function or process that is, the flow of data and external entity
• At this level of data storage possible
• For processes that do not detailed again on the next level then added the symbol ‘*’ or ‘P’ at the end of the process
• Input and output balance (balancing) between 0 to diagram context diagram should be maintained
• How to make it ? :
  1. Determine the main process in the system.
  2. Determine what is given / received each process to / from the system while considering the concept of balance (the data flow outgoing / incoming from a level should be the same as the flow of data entry / exit to the next level).
  3. If necessary, store peeping up data (master) as the source and destination flow data.
  4. Draw diagram level zero.

- Avoid the intersection flow data

- Give the number on the main process (the number does not indicate the order process).

Detailed Diagram

• Its diagrams that decompose a process that is in the diagram zero level or above
• Numbering level in the DFD:

• In the one level there should be no more than 7 units and the maximum of 9, when more should be done in the decomposition

SPECIFICATION PROCESS

• Each process in the DFD must have a specification process
• At the top level method is used to describe the process can use a sentence with descriptive
• On a more detailed level, namely on the bottom (functional primitive) requires specification of a more structured
• Specification process will be the guideline for the programmer to make this program (coding)
• Methods used in the specification process: the process of disintegration in the form of a story, decision table, decision tree

EXTERNAL UNIT

• Something that is outside the system, but it provides data in the system or to provide data from the system
• Symbol by the notation
• External entity not part of the system including
• Naming:

1. The name of the form of noun
2. Terminal may not have the same name except the same object

• There are two types of terminator:

1. Terminator Source (source): the terminator of a source.
2. Terminator Destination (sink) is the terminator that was the purpose of data / information system.

• Terminator may be a person, group of people, organizations, departments within the organization, or the same company but outside the system that is being made models.
• Terminator can also be departments, divisions or systems outside the system that communicate with the system that is currently being developed.

DATA FLOW

• It is a place flow information
• Described the straight line that connects the components of the system
• Flow data is shown with the direction arrows and the name on the flow of data that flows
• Flow data flow between processes, data storage and data flow indicates that the form of data input for the system
• Guidelines of the name:

1. Name of the flow of data that consists of some words associated with the flow lines connect

2. No flow data for the same and the name should reflect its content

3. The flow of data that consists of several elements can be expressed with the group element

4. Avoid using the word ‘data’ and ‘information’ to give a name to the flow of data

5. Wherever possible the complete flow of data is written

• Terms of others:

1. Name of the flow of data into a process may not be the same as the name of the data flow out of the process

2. Data flow into or out of data storage does not need to be given a name if:

- Flow of data simple and easy to understand

- Flow of data describes all data items

3. There can be no flow of data from the terminal to the data storage, or vice versa because the terminal is not part of the system, the relationship with the terminal data storage must be through a process

• In addition to indicating the direction, flow data on the model made by the professional system can represent bits, characters, messages, forms, real numbers, and various information related to the computer. Flow data can also represent data / information that is not associated with the computer.

• There are four concepts that need to be in the flow of data representation, namely:

1. Data packets of

When two or more data flows from a source to the same goal and have the same relationship, and should be considered as a single data flow, because the data that flow together as one package.

2. Diverging Flow Data

Flow of data spread shows a number of copies of data packets that originate from the same source to a different destination, or a complex data package is divided into multiple elements of data that is sent to a different destination, or flow data for a data packet that has a different value the will to be delivered to a different destination.

3. Converging Data Flow

Some of the data flows of different resources to join together towards the same goal.

4. The purpose or the concept of Data Flow

All data flows must contain at least one process. The purpose is this sentence:

1. A data flow resulting from a process and to a data store and / or the terminator (picture (a)).
2. A data flow generated from a data store and / or terminator, and leading to a process (picture (b)).
3. A data flow resulting from a process and to a process (picture (c)).

PROCESS

• The process is what is done by the system
• The process can process data flows or data entry into the flow of data out
• The transform function of one or more of data input into one or more of the output data in accordance with the desired specifications
• Each process has one or more inputs and produce one or more output
• The process is also often called bubble
• Guidelines of the process:
  1. Name of the process consists of a verb and noun, which reflects the function of the process
  2. Do not use the process as part of the name of a bubble
  3. May not have some process that has the same name
  4. The process should be given a number. Order number wherever possible to follow the flow of the process or sequence, but the sequence number does not mean that the absolute is a process in chronological order

DATA STORAGE

• Data storage is a storage place for data that exists in the system
• Symbol by a pair of parallel lines or two lines with one side open side
• The process can retrieve data from or provide data to the database
• Guidelines of the name:
  1. The name should reflect the data storage
  2. When his name more than one word must be marked with the number

• A data store associated with the flow of data only on the component processes, not with the other components DFD. Data flows that connect the data store with an understanding of the process have the following:

1. Flow data from the data store, which means as the initialization or reading one single packet of data, more than one packet of data, part of a single packet of data, or part of more than one data packet to a process (picture (a)).

2. Flow of data to store data as a means Updating data, such as adding a new data packet or more, remove one or more packages, or change / modify one or more packet data (picture (b)).

DFD SYMBOLS

DATA DICTIONARY

• Working to help the system to interpret the application in detail and organize all elements of the data used in the system precisely so that the system analyst and have a basic understanding of the same input, output, storage and process
• At the analysis stage, the data dictionary is used as a means of communication between the systems analyst with the user
• At the system design, data dictionary is used to design input, reports and databases
• Flow data on the global DAD, further details can be seen in the data dictionary
• Load the data dictionary as follows:
  1. Name of data flow: must note that readers who need further explanation about a flow of data can find it easily
  2. Alias: alias or other name of the data can be written
  3. Forms of data: used to segment the data dictionary to use when designing the system
  4. Flow data: indicates from which data flows and where the data
  5. Description: to give an explanation of the meaning of the data flow

BALANCING IN DFD

• Flow of data into and out of a process must be the same as the flow of data into and out of the details of the process on the level / levels below
• Name of the data flow into and out of the process must match the name of the flow of data into and out of the details of the process
• Number and name of an entity outside the process must be equal to the number of names and entities outside of the details of the process
• The issues that must be considered in the DFD which have more than one level:
  1. There must be a balance between input and output of one level and next level
  2. Balance between level 0 and level 1 at the input / output of stream data to or from the terminal on level 0, while the balance between level 1 and level 2 is seen on the input / output of stream data to / from the process concerned
  3. Name of the flow of data, data storage and terminals at each level must be the same if the same object

RESTRICTION IN DFD

• Flow data may not be from outside the entity directly to other outside entities without going through a process
• Flow data may not be from the savings directly to the data to outside entities without going through a process
• Flow data may not be saving the data directly from the savings and other data without going through a process
• Flow of data from one process directly to the other without going through the process of saving data should / be avoided as much as possible

System Concept Investigation

Problem is gap between the goal system and the actual system conditions, with the understanding why other systems failed to achieve the goals that the system has been determined previously. To know the things that have been what caused the failure of the system, the analyst should conduct an investigation before taking action to improve the system. With the investigation, an analyst will better understand the problem and the system flow more depth, even detect the problem is known but the problem still describe the size of the course.

Many reports in the detection problem may not actually be real or can not be solved. This may be because:

a. Goals that are too difficult or ideal so that might not be reached.
b. The system can not be developed because of lack of resources, attitudes, or both.
c. Measurement system that is not accurate.

d. Statement of purpose of the system that is behind (statement of goals is dated).
e. Gap between the ideal system and the system at this time is temporary (the gap between the ideal and the current system is temporary and will decrease given patience).

In solving the problem, should provide an explanation of:

a. The formulating condition of the system that runs through the investigation in detail.
b. Getting a consensus that the ideal system.

c. Develop several alternatives to reduce the difference (gap) between the ideal system with which system is running

d. Selecting the best alternative and sell it to management.

Task start point b to d akan take a very long time including the necessary costs. The objective of the investigation is to stabilize or show the actual problem occurred while analysts as a way to understand the system in depth.

Constraints in the system of investigation

In conducting investigations, there are several barriers or obstacles that will occur, among other issues:

a. Time (time)

Analysts lack of resources (resource) time, so just do some investigative activities. Often top management is only giving a little time to conduct investigations on their system as soon as possible to get results.

b. Cost

Often the costs incurred related to the length of time for activities investigas, so

that management will give the limits of cost. The more time you are treated to make

the investigation so the larger the cost of which must be issued.

c. Science

Manager information systems tend Yunior told analysts that do not yet have

the technical expertise or knowledge is sufficient, so that will impact on the results of

investigations that are less deep, or more mature.

d. Politics

Management or the parties may distribute certain issues which aim to restrict

the investigation activities.

e. Interference.

There are parties who try to intervene or manage investigas in activities

that will disrupt or cause a disruption and the results obtained in accordance with

reality is less available.

Recommendations
Results of the investigation is a recommendation, which is one of them is as follows:

a. Does not take any action because it found no problems. This can happen as they may in the preliminary report, the problem contrived so that at the time of the investigation is done-the problem does not happen or was not found.

b. Perform system maintenance for problems that small. Maintenance of the system that made every day (short period) will help minimize the problems that appear in so fast and to always be better controlled.

c. Increasing the ability or skills in the run or use the information system.
d. Consider modifications to the system in total, so the need to replace it with the thought that the new system.

e. Place going into the development plan system is immediately done.
Investigative tactics

Investigation tactics

a. Listen, do not lecture.

If you know all the answers, you certainly will not conduct investigations. So that in the investigation should provide enough time for the management or the user to explain in clear and complete, and system analysts do not dominate discussion

b. Do not provide solutions to the initial problem    This means do not try showing ideas to solve the problem, before the investigation is completed all the activities carried out, so avoid solutions that part by part.

c. Comparing the story (compare stories).

Different people mean different views of the same problem,
so the need to involve the supervisor and subordinate in the view of the problem clearly and can be trusted. Should not hear from the source 1 so that there is only 1 view. When the user has a difference of views, should find differences and then seek the views that have similarities.

d. Note the reluctance responses (look for reluctant responses).

Reluctance to give responses that indicate something is hidden. Too many problems system also causes confusion, so not able to explain in full.

e. Note the logical inconsistency problems (probe for logical inconsistencies).
Inconsistency is the logical termination of the data flow where data is
missing, or suddenly appear certain data. Some of the things that dealing with this issue:
There are the input of data but no output (black hole).

*There is the output, but no input (miracles).

f. Notice the impact you (observe your effect).

Given the differences of when you attend and when you do not present. Rating referred directly to the internal probe. While external probe is the assessment made by anyone without known (searching external materials), such as by analyzing the report, history the problems of thectools, and sources of other secondary investigation.

g. Require hard work, giving rise to boredom (expect hard, boring work).Be a detective professionals and patient in dealing with problems in phases. And the system is sustainable.

h. Avoid problems politk (avoid politics).

Mission analyst system is not the judge the facts (your mission is the fact,
not judgment).

Investigation techniques

Investigation techniques included :

a. Directly (direct (internal) probes)

Namely to find out directly what is happening in the user environment
They allow you to paying attention to it directly without
through certain parties (interpreter). Internal probes are source of chaos (disruptive), the differences arise because of attitude. Internal
probes used as richer and the justifier of the group facts that occurred (truer group

of facts). There are three techniques for conduct the investigation directly, with:

1. The questionnaire (questionnaires).

This technique is very appropriate, if in the investigation have constraints
time and cost. Although to get it through the form of responde
field. The matters in the questionnaire condition explanations akan akan
different if carried out directly in the face (face to face interview).
This is the best of the questionnaire as a document that can show
differences that occurred in the respondents

2. Frequently asked questions (interview).

These activities require time and special expertise. Not all people able to interview successfully. Interview can be used for the sequence in depth in addition to more flexible
accordance with field conditions. Obstacles faced and the time is
special expertise.

3. Observation.

It is a strong internal probe (a powerful internal probe).
Sit together with the system by making observations with the
question is more specific. Why you do this activity?
or where this document will be moved?. Each question may
be can demonstrate problem solving mysterious

b. Indirect (indirect (external) probes)

Activities that can be done quickly and not visible from
operational personnel, so that they can know the outside or something
hidden from the user community. This activity will dominate
activities at the beginning of the SDLC, the internal probe to deepen.

1. Flow of the procedure (procedure flow).

Operational procedures is the means (vehicles) for new employees
understand their work and experience to handle employee problems.
If the procedure does not flow properly, the system information can not be
also operated correctly. Use the system flowchart for
the path information as an explanation operating procedures.
If there is any problem diprosedur, the problem is probably will
arise in the actual operations.

2. Reviewing documents (document review).

Is to find and collect the documents necessary (critical document). If problems occur in many customer orders, collected from the original source document customer orders that used as its data-entry, interactive screen format, detail
transactions, and summary reports that the error occurred. Documents often caused problems.

3. Sampling.

Maybe you need information from the billing vendor that has been
provide discounts at the time of payment, because the company lost
money when the discount is not given when the delay of payment.
You can involve the customer to get the payer
information (although there are many transactions). Finally you can make
list of sample data with the random selection for the last one week,
select the 20 pages of daily transactions, select 5 items from each
page are selected., record the information for each item and 5
calculate the average-Ra and variants to the sample-sample of all transactions
payment occurs.

4. Tabular (Tabular tools)

Also called the matrix, the check list to find disputes in the transaction flow as follows:

System description

Determine system performance at this time will have difficulty when
company does not have a standard performance measurement system.
Unfortunately, companies tend not to update documentation systems that are running. Therefore, to improve the document analyst system for investigating the problem.
Description of the system include a clear explanation at this time:

a.Inputs
b.Outputs
c.Files
d.Data elements

e. Volume of transactions and documents action

f. Data flow diagrams

NEEDS ANALYSIS

In doing this step will be achieved 4 goals, namely:

a. Describe the system at this time in full.

b. Describes the ideal information system.

c. Bringing information system to the ideal conditions at this time with
attention to resource constraints.

d. Giving impetus to the confidence of this team into the development
system

. Requirement analysis phase is the intensive interaction between the analyst
system with the community system (end-user), where the development team
system shows the expertise to get the responses and confidence the user, so get a good participation. Is working hard to get agreement user skeptical about their needs from an information system, as they may the failure of the previous information system.

The desire Requirement in the first stage of the system is doing a survey of
the desire and the ideal information system. Here is an ideal concept than a reality, meaning that no the ideal system (no system is perfect information) but are subjective. If this is not explained in depth can rise to differences of views will be disappointing or end-user. Method needs analysis.

Keep the selection method of collecting data for the right to do
requirement system. Methods are interviews, questionnaires, observation, analysis procedure, and document the survey.Each method will be described in depth as follows:
Frequently asked questions (Interviews)

1. How do the methods used.

· Elections potential interviewees.

· Make arrangements to potential interviewees.

· Setting up the structure of a complete and clear.

· Choosing the person personally and diinterview recorded.

2. Target of the method.

· private key in the process of DFD.

· Sometimes involve outsiders, such as customers or vendors.

3. Benefits of the method.

· interviewer can measure the response through the questions and to adjust them according to the situation that occurred.

· Good for the problems that are not structured, such as why you think this could happen?.
Demonstrating the effect of interviewer time.

· create a high response since the preparation meeting.

4. Loss method.

· Requires time and cost is not small.

· Requires special training and experience of the interviewer.

· It is difficult to compare the interview reports as natural subjectivity.

5. When both methods are used.

· Obtain or view a description of key personnel.

· Test the credibility of the interviewees.

· Search for the interview unsureness or contradictions.stabilizing credibility team. Some important factors in both the interview, namely objektives,
audience, format, weighting and combining responses, and docummentation.

Questionnaires
1. How do the methods used.

· Design using standard questionnaires.

· The questionnaire sent to a work environment end-users.

· Structure of the response statistics summarized in the distribution.

2. Target of the method.

· All end-user with their knowledge will be involved in the process of solution
splitting system.

· End-user associated with the use of symbols in a DFD.

3. Benefits of the method.

· Cheap and fast from the interviews.

· Not require a trained investigator (only one expert who needed to design a questionnaire for the end-user selected.

· Easy to mensintesis results since the making of the questionnaire.

· With easy-to minimize the cost for all end-user.

4. Loss method.

· Unable to make a specific question for the end-user.

· Analyst does not involve an impression so that can reveal personal end-user.

· response to a low not because there is a strong encouragement for return the questionnaire.

· Unable to adjust the question to end-user specific.

5. When both methods are used.

· simple question, and have no meaning fork.

· Requires a broad perspective of the end-user.

· If you have less time and cost.

Observation

1. How do the methods used.

· Personally visit the location of one analyst observed.

· Analysts recording events in the location of the observation, and including volumen processing, spreadsheets.

2. Target of the method.

· geographic location of the process shown in the DFD (Data Flow Diagram)

3. Benefits of the method.

· Get the facts from the records of opinion.

· Not require construction of a question.

· Do not disrupt or hide something (end-users do not know
that they are observed).

· Analyst does not rely on oral explanations from the end-users.

4. Loss Method

· If visible, analysts may change the operation (end-user was observed).

· In the long term, the fact that in one observation may be not appropriate (representative) in daily or weekly.

· Requires experience and special kehlian analyst.

5. When both methods are used.

Require a quantitative description, such as time, volume and so forth. the suspicion that the end-user to the actual occurrence of a does not occur (contrived).

Tip in the practical observations:

a. Do not be observed in a long time.

There are two reasons, namely: with a long time will disturb the operation
which is being observed, and will deflect the real problems.
b. Create a brief note.

c. Before observations, please let the supervisor and the involved
about what will be done and why, so it will reduce interference.

d. Use a short checklist of the required information together

e. Do not make observations without a plan

Procedure Analysis

1. How do the methods used.

• The operating procedures can identify and learn document the flow of key information through the system, with data flow diagram (DFD).

• Each flow key document describes the procedures operating system.

• Through observation, learn the facts of the analyst describe your volume of distribution (high, low, medium) and what the next to be a copy of the original document.

2. Target of the method.

• Documents in the main DFD (Data Flow Diagram)

• The process in the DFD.

3. Benefits of the method.

• Evaluation procedures can be done with the intervention (interferences) is minimal and does not affect the operation.

• Procedures can flow into a structure checklist for make observations.

4. Loss method.

• procedures may not be complete and not up to date again.

• Learning the flow chart document takes time and expertise analyst.

5. When both methods are used.

• decide whether the failure of the system can help design good.

• The analyst is not completely familiar with the document flow.

• describe your document that disrupt the flow of work function.

Observations document (Document Survey)

1. How do the methods used.

• Identifying the main documents and reports (physical data flow diagram).

• Collect copies of actual documents and reports.

• Any documents or reports, is used to record data, including field (the size and type), frequency of use and coding structure.

2. Target of the method.

• Flow data key shown in the data flow diagram (DFD).

3. Benefits of the method.

• Minimize interruptions of operations functions.

• The beginning of the data element dictionary.

• Often, you can consider the major procedural modification.

4. Loss method.

• Requires enough time (there is a business organization in the swamped with documents and reports).

5. When both methods are used.

• Must be done if a system will be designed (for activities analysis, clarity in the new system design and analysis documents can help to determine the next task of the design).

Sampling
Sampling can help reduce the time and cost. Need for accuracy select a sample of the population, so the statistics that require expertise not experience a failure or threat.

Resource constraints

a. Time

Changes a system must be expressed in the framework since decreasing function of the system quickly. Time constraints can be influence the analyst to consider the technology innovation that is not may be operated in a short time. Therefore, the need to need enough time to have a leeway of time so that can create the most good alternative.

b. Money

The ideal information system will require that the cost of expensive, so requires adequate funding. This will occur due to competition with our competitors where they embed investment in a large information system.

c. Expertise.

Staff information system may not have knowledge or experience a significant problem, such as telecommunications, database integration, and interactive setting. Companies can to take a contract with consultant to increase design capabilities. This will hope constraint costs incurred for energy consultants.

d. Technology.

Technology needs may become the main problem in supporting working system so the need to pay attention to the development of technology continues again, the consequences of going in cost and not until the technology used behind the competitors.

e. Ekternal factors.

Many of the constraints that come from outside of the design settings, such as prevention use exotic technologies, to prevent keep local data in a central database system, and so forth.

Needs analysis document

1. Referral (conduct) analysis.

• Relationships with end users.

• Analyze records, forms and reports.

• Observation process.

• Analyze methods used.

• Problems in collecting data.

2. Needs of the user.

• What are the actual needs.

• reporting requirements (type and frequency).

• Needs training.

• The influence of the new system.

3. Constraint system.

• Explain the constraints of time, cost, expertise, technology and factor ekternal.

• realistic system.

4. Documentation.

• Intrumen data collection (needs questionnaire, interview).

• Consensus statistics.

• Flow of data in logical and phisik.

• Element data early in the dictionary.

GENERATINGSYTEMS ALTERNATIVES

A strategy choice

Management options to create top-level strategy with all the attention
constrain. selection strategy used is as follows:

Distributed versus centralized processing

Currently, there is a tendency changes occur from the information the decision
centralized data processing to the end-user Decentralized responsibility Centers. Distributed environment in the process, end-user disconnect the equipment,
and implementation of priority development. On the other there is a growing number of end-user to enter the world computer. They try the latest technology without considering the cost, and risk. Without expertise, the system will be in the environment
conservative.

Integrated versus dispersed databases (database system spread)

When organizations use a database system spread, the system consideration has the option of what files are included in the database and the data are entered in the file. Integrated database by the administrator maintain a database of all control data
storage, access and modification. Management decides on the appropriate level with a choice of the designer considers the system with ease control.

Surround strategy of system development

System development strategy is important because many companies have a stack (backlog) of the new system is designed and conditions system that is currently being modified. This strategy allows the system designer differences in language use of the program and run it on a computer different for a full compatibility of the system (a totally compatible system). Strategy around the environment is very important in the problem corporate takeovers, in which one company to get the company and information systems may not compatible with (different).

Options tactics

Management decide now or later, the opponent modifications, and
SDLC configuration. Election was conducted before the selection operation. Eight options on the design operational Design choices are grouped into input, processing, and output. Each group can have the following options:

a. Input

1.On-line versus off-line data entry. Off-line data entry does not have the ability to validate the good transaction immediately. Therefore, the on-line data entry still used in the recommended system configuration information.

2. Keyed versus machine-readable data entry. Machine-readable data entry can increase speed, reduce income data errors, and save costs for worker (save human costs). However require a large investment in the equipment and maintenance.

3. Centralized versus Decentralized data entry. Decentralized entry is faster but the error level high because many users who enter data. Machine-readable entry requires decentralization of income benefit speed in the process of capturing data source (point of sale).

b. Processing

4. Batch versus real-time update record. Batch processing the update rekord long, suitable for centralized data entry. Real time processing costs equipment and increase the speed of the process.

5. Sequential versus direct access to records. Sequential access is associated with batch processing. Direct access to the related real-time processing.

6. Single versus multiple-user update of records. Design a system for multiple-user more complex in security access and update the record simultaneously. Complexity occurs when the speed of the process is important and application with real-time process.

c. Ouput

7. Traditional versus turnaround documents. Traditional document is a document of how to record-keeping system done through the keyboard (key input). Turnaround documents are data collection system to be done through the engine of a document

8. Structured versus inquiry-based reports. Structured report is created in a standard format and provided the routine, while the inquiry-based reports are based on demand accordance with the format of this request. Oftentime inquiry-base report found in the environment where real-time data must be accessed quickly.

SELECTING THE PROPER SYSTEM

In this phase (SDLC), a number of alternatives that have made it necessary to
compared so that one can find only the best system.
Each alternative system that has been compared with fixed
the condition of the system at this time. Note, at this time that the system can
resumed in the form of a new replacement system. If a candidat
system does not provide the benefits of the system compared lebh
at this time, the system at this time will still be used, so that the system
replacement should really benefit and the benefit exceeds
system is now the most.

Comparison Tactics

System based on the comparison of costs and benefits relative. Cost
is the demand for the payment pengoperasi and information systems.
The advantage is the value or condition as a result of the implementation of additional
information systems. These matters include the level kesalahaan
(error rates), increasing sales (increased customer sales), and
speed response time. The advantage is difficult to be measured
as qualitative (not just a number only descriptive).
Increase customer satisfaction and reduce the resistance (end-user
resistance) is a qualitative advantage. The advantage is the opportunity
to increase (improve) the benefits the company.

There are three ways a system (A) can be more superior than the other system (B).

1. Have a lower cost than B, and both systems have same benefits.

2. Have a lower cost than B, and A will also have the advantage more than B.

3. A and B cost the same, but A has the more advantage.

Method for system Comparation

There are 4 methods used to compare two or more
information system, namely:

a. Break-even analysis (BEP)

b. Payback period

c. Discounted payback period

d. Internal rate of return (IRR).

Cost category

Basically the costs are divided into categories:

a. Hardware: Mainframe, minicomputers, microcomputers, and peripherals equipment.

b. Software: systems, utilities, and application software.

c. People: analysts, programmers, operators, data entry personnel, and so forth.

d. Supplies: paper, tapes, disks, and so forth.

e. Telecommunications: modem, local area network cabling, multiplexors, front-end processors, and so forth.

f. Physical site: air conditioning, Humidity control, security, and so forth.

Nature of costs

Comparing the cost of information systems through the life of the system, analysts
memproyeksi how the cost changes for the future. To do so,
there are three models of information systems operating costs, namely:

a. Linear.

b. Exponential.

c. Step function.

When costs occur

Cost information system can occur once or continuously.
On-time costs, development costs are related to the development
system, and recurring costs, operational costs are related to
operating system information every day. The difference between one-time
(development) and recurring (operational costs) is often out of choice
material (matter). For example, the purchase of a computer is a one-time
development system, while the rent the same computer is a recurring
operational cost. Use the following to set daftat costs:

a. One-time (development) costs.

1. Hardware purchase.

2. Software purchase.

3. Analysis, design, programming, testing and personnel hours.

4. Preparation of computer sites.

5. Initial training and orientation of users.

6. Docummentation for new system.

7. Changeover from old to new system.

8. Conversion from old to new file format.

b. Recurring (operational) costs.

1. Hardware and software lease.

2. Hardware and software maintenance contracts.

3. Day-to-day personnel cost including analysts and programmers, computer operations, data entry operators, and end-user costs.

4. Computer supplies.

5. Telecommunication costs.

6. Site computer rental or lease.

7. Ongoing training.

The information system

Some of the factors that lead qualitative performance information systems that either:

a. Reduce the error level (increased accuracy).

b. Reducing the time to fix the error.

c. Reduce the response time of interactive workstations.

d. Accelerate the provision of the report (information).

e. Improving the security system.

f. Propagate update the source record is active.

g. Increasing user satisfaction. Several factors can be measured, but not in money.

The company’s strategy

Information system can make a profit in the company kompetetif.
Increase profit at this time, however, is difficult to
estimated. The increase in profit does not occur often in sudden,
but occurred several years after the implementation of the new system.
When two alternatives to a system of similarity comparison, open-door
factors to consider strategies for the company.

There are factors the company strategy is as follows:

1. Customer satisfaction (customer satisfaction).

An information system may cause the circumspection efficient products and consumer desire. Increase customer satisfaction will no doubt increase sales. Such as increased sales, however, difficult to predict and quantitative.

2. Increase sales (increased sales).

Point of sales system (POS) of free storage tasks rekord. Management expect sales staff time devoted to business. This marketing and increase sales. The only sales will increase the difficulty to predict in the money.

3. Consumer commitment and vendors (vendor and customer commitments).

Company designing an online feedback system and allow consumers direct access to the system. Consumers are now locked (depending) on this system so that a commitment to faithful (pleased) at the company. Consumer and vendor commitment difficult to predict.

4. Information product marketing.

Often, new information system can be used by other companies. As the American Airline system provides information marketing products during 1970, the company developed a system of booking ticketing and marketing system and is also used by service other airlines, so that a product is profitable.

CONTINUING DECISION OR NOT

a. If the company decided to develop the information system, the department will do the next process, namely Design System.

b. If then the System Development Life Cycle (SDLC) will be terminated.

c. Will often found problems with the system and the study and top management will usually ask for the fulfillment of the re-study system.

d. Model will describe some of the stages of the repeated and sometimes the information will make a decision before the repeat stage system of study.

e. With the alternative, the decision to repeat a previous phase or not is Go – No-Go Decision.

WHY THE INFORMATION SYSTEM MUST BE DEVELOPED ?

• There are problems

The problems that often happened is when the old system can’t operating goodness or the performance is inappropriate with the expected so it can’t fulfilling the information need that develop more and more, so the new information system must be developed.

• The problem in the organization growing system

Because of the fast growing of a organization, so oftentimes the problems are happened in the information system. The problems like the insinceritys in the data manipulation so the information that we got is inappropriate with the fact . so, the more safety information system must be developed.

• To reach for the opportunities

In the more competing market, the speed of the information is very determining the successfully of a company to make a decision according to the strategi that have already made to get every existing oppurtunities. If the company can develop their information system good, so the company can reach for every opportunity to developing their company, so the opportunity is not move to the competitors.

• There are the instructions

The developing of information system can happened because there are the instruction from the superior to moving forward their company. Besides, can happened because of the organization eksternal factors, like : tha government’s regulations.

THE GOAL OF DEVELOPING SYSTEM

• Solving the problems that happened related with the current information and the quality of the information
• Reach for the opportunities to develop the company
• Fulfiling the instruction that to be given by the superior and also the influence from the eksternal factor (example : the government’s regulations)

WHAT IS EXPECTED FROM THE NEW SYSTEM ?

• The performance

- The most expected from the new system is the performance better than the older system, it can measured from the throughput and the response time system

· Information

- The increase of the quality of the information. The information that reach for must be according to what we want

· Economy

- The increasing of the benefit vs the decreasing of the expense. Reach for the information is good with the minimum expense

• Control

– With this new system, we expected it can decreas the information mistakes that we reached.

• Efficiency

– With the small resource can reach the expected information.

• Services

– With this new system can increase the services that to be given better than the older system.

THE PRINCIPLES OF THE DEVELOPING SYSTEM

· System to the management

· System is a big investation

- Investigation all of the alternative (decreae the lose opportyunity cost)

- The best Investigation must has a value : cost benefit analysis & cost effectivenes analysis

· The system is need the ecutadely person

– Musn’t in formal education

· The step of the work à System development life cycle

• The developing of the system is musn’t ascending

• Dont afraid to cancel the contract

• The documentation of system

WATERFALL MODEL

• Characterized by

– Sequential steps (phases)

– Feedback loops (between two phases in development)

– Documentation-driven

• Advantages

– Documentation and clearly defined phases

– Maintenance easier (assuming up-to-date docs available)

• Disadvantages

– Complete and frozen specification document up-front often not feasible in practice

– Customer involvement in the first phase only

– Sequential and complete execution of phases often not desirable

– Process difficult to control

– The product becomes available very late in the process (significant risk of building the “wrong” system)

• Applicability

– Only appropriate when the requirements are well-understood

SPIRAL MODEL

• Waterfall model plus risk analysis and prototyping preceding each phase and evaluation following each phase

– Inner cycles denoting early system analysis and prototyping

– Outer cycles denoting the rest of the classic waterfall

• Radial dimension: cumulative cost to date

• Angular dimension: progress through the spiral

• If all risks cannot be resolved, the project is immediately terminated

• Appropriate only for big projects (high management overhead)

– First proposed by Boehm in 1987

– Precursor of iterative models

ITERATIVE MODEL

• Build software in multiple iterations

• Two flavors

– Incremental

– Evolutionary

Incremental Model

• User requirements are prioritized and the highest priority requirements are included in early increments

• Each release adds more functionality, i.e., a new increment

• Advantages

– Operational quality portion of product within weeks (whereas in waterfall and rapid prototyping models Operational quality complete product at end)

– Less traumatic

– Smaller capital outlay, rapid return on investment

– Comprehensive spec up front can be used as a contract

• Disadvantage

– May be hard to create a comprehensive requirements spec up front if a domain not well understood

Evolutionary Model

• Advantages

– Early increments act as a prototype to help elicit requirements for later increments

– Constant customer involvement and validation

– Allows for good risk management – lower risk of overall project failure

– Project can be continued as long as each increment delivers value

– Agile software development methods use the evolutionary model

• Disadvantages

– Build-and-fix danger

• Can use agile development practices (unit test, increment planning, etc.) to avert this danger

– Not appropriate when a larger part of a system needs to be commissioned from a supplier

• Need a comprehensive requirements spec as a contract up front

THE APPROACH OF DEVELOPING SYSTEM

• The classical approach vs the structures approach

– The classical approach

• The steps in SLDC

• It isn’t involved the user, more drawing nearthe analys system

• The problem : the difficult ot the develop, the high cost of the treatment, the mistake possibility is big, the successfully is less guaranted, the promblem in implementation

– The structures approach

• The user is involve early to determining the system’s need

• Use the tools like data flow diagram

• The rasher approach vs the system approach

– The rasher approach

• Emphasizing to a application or activity

• It isn;t bothering enterity target.

– The system approach

• Look the system as a intact unity

• Emphasizing to the periodic attainment

• The bottom-up approacg vs the top-down approach

– The bottom-up approach

• Starting from the bottom level, that is operational

• It is the classical approach charateristic

• Known as data-analysis

– The top-down approach

• Starting from the top level, that is strategy planning

• It is a structures approacch characteristic

• Also known as decision-analysis

• The totally-system approach vs the moduler approach

– The totally-system approach

• Developing the system at a time and totally

• It is a classical approach characteristic

– Pendekatan moduler

• Breaking the complicated system to be the simple part

• The developing system be on time, easy to comprehended and take care

• It is the structures approach characteristic

• The great-loop approach vs the evolutionary approach

– The great-loop approach

• Developing the system at a time that use the recent technology

• Has a high risk and take a high cost

– The volutionary approach

• Applying the recent technology for the certain applications

• Developing to follow the need

• Economically in cost and can follow the developing of the technology

THE DEVELOPING SYSTEM METODOLOGI

• What is metodoligi ?

– The methods that use in science

• What is method ?

– A systematic way to do something

• What is algorithms ?

– The ascending procedure to solve a problem

THE CLASSIFICATION OF DEVELOPING METHOD

• Functional decomposition

– Emphasizing to resolving the system to be the sub system

– Example: HIPO, Stepwise refinement, iterative stepwise refinement, information hiding

• Data-oriented

– Emphasizing to the characteristic of the data that processed

• Data-flow oriented: The modules are according to the data element’s type

• Data-structure oriented: input and output structure

• Prescriptive

– Usually provide by the software maker factory

THE TOOL IN THE DEVELOPNG SYSTEM

• In form of graphically : HIPO, SADT, Jackson’s diagram, and the other

• The tool that use diagram :

– Activity charting: describing the activity, example: Gant chart, flowchart, and the other

– Layout charting: describing the arranging situation

– Personal relationship charting: describing the personal relationship, example: organization chart, working distribution chart

THE TECHNIQUE OF THE DEVELOPING SYSTEM

• The project manajement technique à for scheduling the project, example: CPM and PERT

• The technique to find the fact àfor collecting and determining the data/fact

– Interview

– Observation

• The analysis of cost/benefit cost-benefit dan cost-effectiveness analysis

• The technique to running the meeting

• The inspection technique

THE ANALYS SYSTEM & PROGRAMMER

• The analys syatem : learn the problems and determining the need of the user’s system to identify the solving

• The programmer : write the source code persuant to the designing that made by the analys

• The analys system is undertaking to link the diffrence of knowledge that happened between the user and the programmer

THE KNOWLEDGE THAT NEEDED

• The technology in the processing of data, computer, and programminf

• The common bussines knowledge

• The quantity method : regresi, linear programming, and the other

• The ability to solve the problem

• The ability for communication between the personnel

• The ability to constructing the relationship between the personnel

Before learn more about the analysis and information system design, there are some basic concepts that we must comprehended before. The concepts are :

• What is The System ?
• What is The Information ?
• What is The Information System ?
• Who is involve in The Information System?
• Why The Information is needed ?
• How is the way to develop the Information System ?

But we only study about the meaning of the information in this first class. For more explaination will explained as following :

The Definition of The System

The first that will explained is the definition about its system. In fact there are many approach about the definition of the system, but in this time just only explained two approach about the system, there are the procedure approach and the element approach.

The Procedure Approach :

The system is a work network from the procedures that correlate each other, gathering together to do an activity or to finishing a certain goal. While the Procedure is a precise medley from the instruction steps that explain what must did, who is doing, when to be done, and how to do it. According to the definition above, so with the system procedure approach we can depicting as following (for example : the student registration system ) :

From the pitcure above, we can see the student registration system is a corps of the procedures that correlate each other, starting from registration in the administration office, the adding of the student’s data in the administration office, to the last the student can follow the lecturing in the classroom. All of the procedure is correlate each other so the goal of the system is reached.

The Element Approach

System is a corps from the interaction elements to tired a certain goal. Diffrent from the procedure approach, in this approach the system is depicted as an object that has certain parts that interaction each other to tired a certain goal. Like a human being who has the bone and muscle as a body activator system.

So, with both of the approach we can concluding that The system must :

• Have a goal, and
• Have an objective

So, if we haven’t both of the things above yet, hence it can’t refered as a system because it is imposible to make a system without a certain system.

The Characteristic of The System

A system has some characteristic as following :

• Components

A system has components that interaction each other that forming an unity. A system also can be the component from the other system or it also refered as subsystem. Some subsystem can interconnected each other that forming a bigger system, or it often referred supra system. For example : The components that build the lecturing are the students, the lecturers, the officer, the equipments, and the other.

• Boundary

A system must has a boundary with the other system or with the environments. The aim is to bound the system’s scope so the system can work efficiently without the trouble from the environments so that the goal of the system can reached.

• Environments

Is everything outside from the boundary of the system that influencing the operating system. There are 2 kinds of environments, they are the environment that have a positive characteristic to the the system and the environment that have a negative characteristic. For example the environment that have a negative characteristic is the competitor of our company

• Interface

Is a link between a sub system with the other sub system. It is very important in the system with the big enough scale, because without the interface hence the interaction between the sub system is never functioning.

• Input

Is a energy that entered in to the system, it can as a maintenance entered or a signal entered. For example in the student academic system, the data for each course that taken by the studentis an input from that system.

• Output

Is a the result of the energy that processed and classified to be a useful output. For example the student academic system, the input is the point of the cource that taken by the student, while the output is a transcript of the student’s point.

• Process

Change an input to be an output. Process is the core of in a system. Without a process, hence the output can’t yielded, so the goal of the system is also can’t be reached.

• Objective/Goal

If don’t have a goal, hence the operation of the system will not have a usefulness. System will be usefull if it has already hit the goal.

The following is the depiction from the system of the characteristic that has already explained before :

Note :

I : Input

P : Proses

O : Output

The Classification of A System

Definition 1

Abstract System : Existing system because the ideas, for example: The Religion System, The Custom System

The Physical System : The system that existing physically, for example :Computer system, accounting system, production system, and the other

Definition 2

The Natural System : The system that happened because a naturally process, for example : The earth rotation, the gravitation system, and the other

The Artificial System : The system that existing because the interaction between the human being and the machine, for example : The computer system, The Information System, and the other.

Definition 3

The certain System : System that operating with the predictable behavior, for example : The computer system

The Indefinite System : The Condition of the system can’t predict in the future, for example : The marketing of the product

Definotion 4

The Close system : The system that doesn’t correlate and affect with the environment

The Open System : The system that correlate and affect with the environment.

THE DEFINITION OF INFORMATION

The information is the data that processed to be a better form and more usefull for the receiver. Without processed, data is nothing. For more explaination will explained from this cycle information :

The Quality of The Information

Accurate

The Information is free from the mistakes and don`t deflect or mislead.

Timely

Incoming information to the receiver may not lose time

Relevantly

The information is usefull for the user.

Value Information determined from two matter, that is expense and benefit to getting it. Information will be valuable if it give more benefit than expense to get it.