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Tugas Normalisasi

2009-05-03T06:06:00.000-07:00

Mapping of ERD image above:

1NF/First Normal Form

A form of normal relations, said the first, if and only if every attribute value for every single line. Each field is only one definition, is not a collection of words that has two meanings, one meaning only and not the fraction is also the word - th

e word means so that the other. There is no set of attributes that\ repeatedly or attribute double value.

2NF/Second Normal Form

Second Normal form (NF 2) is:

1). Meets 1 of NF (normal first).
2). Non-key attributes must depend on the function key / primery key.
So that the second normal form for each table / file must be specified attribute keys.

3NF/Third Normal Form

Definition of Third Normal Form (NF 3) is:
1). Meet the 2 forms of NF (both normal).
2). Non-key attributes do not have a transitive dependency on the key / key primery.

Database Normalization

2009-04-26T06:00:00.000-07:00

Normalization

There are several processes that must be done to design a database, namely:

1. Gathering user needs / business

2. Develop the ER model based on user needs / business

3. Converting E-R Model to relationship gathering ( of tables )

4. Relationship normalization to eliminate the anomaly

5. Implementation to database by making table to each; every relationship is normalization

Normalization of Data Bases

Normalization is process of forming of structure of data bases so that most ambiguity can be eliminated. Normalization Phase started from lightest phase ( 1NF ) tightest till ( 5NF). Usually only come up with the storey; level 3NF or BCNF of because have adequate enough to yield the tables which good with quality.

Normalization should be performed for the optimal structure-structure of the table, Increase speed, remove the same income data, more efficient use of storage media, Reducing redundancy, Avoiding anomalies (insertion anomalies, deletion anomalies, update anomalies), improved data integrity.

A tables told by goodness if fulfilling 3 criterion :

· If there is decomposition of is tables of, hence decomposition have to be secured ( Lossless-Join Decomposition

· The looking after of functional depending at the (time) of data change ( Dependency Preservation).

· Don’t impinge the Normal Boyce-Code of Form ( BCNF)

If the three criteria (BCNF) can’t 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.

· Symbol used is (→) to deputize the functional dependency

· Notation: A → B

“A” And “ B” is attribute from a tables. Mean functionally A determine the B or B of depend on A, if and only if there is 2 data line with the same value A, hence assess the B also is of equal

· Notation: A /→ B Or A x→ B

Is reverse from previous notation.

Functional Dependency (FD)

NRP -> Name

· Mata Kuliah, NRP-> Value

Non Functional Dependency:

· Mata Kuliah -> NRP

· NRP -> Value

Functional Dependency from tables of value

· Nrp -> Name
Because for each value Nrp the same, then the value of the same name

· (Mata_kuliah, NRP) -> Value
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 -> NRP

· NRP -> Value

FIRST NORMAL FORM (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) not allowed:

Attribute values, many (Multivalued attributes).
Attribute a composite or a combination of both.

So:

Price is the domain attribute must be atomic rates

Example:

Ex Student Data as follows:

Ex Student Data as follows:

Second Normal Form - 2NF

Normal form 2NF fullfiled in a tables of if have fulfilled the form 1NF, and all attribute of besides primary key, intactly own the Functional Dependency of at primary key. A tables

do not fulfill 2NF, if there is attribute which its depending only have the character of the just just parsial ( only depend on some of primary key) . If there are attribute which do not own the depending to primary key, hence the attribute have to be moved or eliminated.

- Functional depending of X → Y told by full of if vanishing a attribute A from X mean the Y shall no longger hinge functional.

- Functional depending of X →Y told by partial of if vanishing a attribute A from X mean the Y still hinge functional.

- Scheme of Relationship R in the form of 2NF if each every attribute of is non primary key A € R hinge full of by fungsional at primary key R.

- Tables in the following is fulfilling 1NF, but [do] not the inclusive of 2NF :

{NIM, KodeMk} → NameMhs

{NIM, KodeMk} → Address

{NIM, KodeMk} → Matakuliah

{NIM, KodeMk} → Sks

{NIM, KodeMk} → LetterValue

- The tables require to decomposition become some up to standard tables 2NF

· Functional dependency:

{NIM, KodeMk} → LetterValue (fd1)

NIM → {NameMhs, Address} (fd2)

KodeMk → {Matakuliah, Sks} (fd3)

· becoming :

fd1 (NIM, KodeMk, LetterValue) → Tables Value

fd2 (NIM, NameMhs, Address) → Tables of student

fd3 (KodeMk, Matakuliah, Sks) → Tables MataKuliah

Third Normal Form - 3NF

Normal form 3NF fullfiled by if have fulfilled the form 2NF, and otherwise there is attribute of is non primary key owning depending to attribute of is non primary key the other ( depending transitif)

· So that the tables require to didekomposisi become.:

· Student (NIM, NameMhs, Jalan, KodePos)

KodePos (KodePos, Provinsi, Town)

Boyce-Codd Normal Form (BNCF)

Boyce-Codd Normal Form constraint has a stronger form of the Normal third. To be BNCF, relations must be in the form of Normal To one 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 l

ed by one of the 2 seminar. Each leader can only take one seminar course. NPM in this example and show the seminar.

Relations Seminar is a form of Third Normal, but not BCNF. Seminar Code because the function depends on the teach, if any teach can only teach a seminar. Depending on the seminar isn’t a super key attributes such as required by BCNF. So seminar relations must be parsed into two namely:

Fifth and fourth Normal form

Relations in fourth normal form (NF 4) if the relation in BCNF and does not contain a lot of dependence 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.

References:

Er Ngurah Agus Sanjaya. Slide Part 6 - Normalisasi.

DATABASE AND ER-DIAGRAM

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DATABASE AND ER-DIAGRAM

DEFINITION OF THE DATABASE:

A set of data stored in the magnetic disk, optical disk or other secondary storage. Collection of integrated data-related data of an enterprise (company, government or private). for example:

1. Company data > manufacturing production planning, actual production data, data ordering materials, etc.

2. Hospital > patient data, doctor, nurse, etc.

DATABASE MANAGEMENT SYSTEM

DBMS is a system and the data base on the computer. This system is designed to be able to do a variety of data with some reference data are the same. DBMS is able to access various applications.

BIT, BYTE, FIELD

1. >>Bit is the smallest pieces of data that contains the value 0 or 1

2. >>Byte is a set of bit-bit similar

3. >>Field is a set of byte-byte similar, in the database used the term attribute

ATRIBUT/FIELD

It is the nature or characteristics of an entity that provides provide detail on these entities. A relationship can also have attributes.

Examples for attributes:

STUDENTS: NIM, NAME, ADDRESS

CAR: NOMOR_PLAT, COLOR, TYPE, CC

TIPE-TIPE ATRIBUT

Single vs multivalue

Single > can only be filled at most one value

Multivalue > can be filled with more than one value with the same type of

Atomic vs composition

Atomic > can’t be divided into the attributes of smaller

composition > is a combination of several attributes of a smaller

Derived Attribute

attribute value can be derived from other attribute values, for example: age of the attributes generated from the date of birth.

Null Value Attribute

Attributes that have no value to a record

Mandatory Value Attribute

Attributes must have values

RECORD/TUPLE

It is a line of data in a relationship, and consists of a set of attributes where the attribute is to inform each other entity / relationship fully.

ENTITY/FILE

File is a collection of similar records and have the same elements, the same attributes but different data value.

File Type

File is a collection of notes and similar elements have the same, the same attributes but different data values. In the process of application, the file can be in the category with some of the following types

1. Master File

2. Transaction File

3. File Report

4. File History

5. File Protection

6. File Work

DOMAIN

Domain is the set of values that are allowed to reside in one or more attributes. Each attribute in a database relasional is defined as a domain.

KEY DATA ELEMENT

Key elements of record which is used to find these records at the time of access, or can also be used to identify each entity / record / line.

SPECIES OF KEY

Superkey

is one or more attributes of a table that can be used to identify entityty / record of the table are unique (not all attributes can be superkey).

Cadidate Key

is a super key with minimal attributes. Candidate must not contain a key attribute of the table so that the other candidate key is certain superkey but not necessarily vice versa.

Primary Key

One of the key attributes of the candidate can be selected / specified a

primary key with the three following criteria:

1. Key is more natural to use as reference

2. Key is more simple

3. Key is guaranteed unique

Alternate Key

is an attribute of the candidate key is not selected to be primary key.

Foreign Key

is any attribute that points to the primary key in another table. Foreign key will be going on a relationship that has kardinalitas one to many or many to many. Foreign key is usually always put on the table that point to many.

External Key

is a lexical attribute (or set of lexical attributes) that values are always identify an object instance.

ERD (ENTITY RELATIONSHIP DIAGRAM)

ERD is a model of a network that uses word order is stored in the abstract system.

Differences between the DFD and ERD:

- DFD is a model of network functions that will be implemented by the system

- ERD is a model that emphasizes the network data on the structure and relationship data

ELEMENTS OF THE ERD

Entity

In the ER Diagram Entity is described with the form of a rectangle. entity is something that exists in the real system and the abstract where the data stored or where there are data.

Relationship

ER diagram on the relationship can be described with a lozenge. Relationship is a natural relationship that occurs between entities. In general, the name given to the verb base making it easier to do readings relationships.

Relationship Degree

is the number of entities participating in a relationship. Degree which is often used in the ERD.

Attribute

is the nature or characteristics of each entity and relationship

Kardinalitas

tupel indicates the maximum number that can be berelasi with entities on the other entity

RELATIONSHIP DEGREE

Unary Relationship

model is the relationship between the entity originating from the same entity set.

Binary Relationship

model is the relationship between 2 entities.

Ternary Relationship

is a relationship between the instance of 3 types of entities are unilateral.

KARDINALITAS

There are 3 kardinalitas relations, namely;

One to One:

Level one to one relationship with the one stated in the entity's first event, only had one relationship with one incident in which the two entities and vice versa.

One to Many or Many to One:

Level one to many relationship is the same as the one to many depending on the direction from which the relationship is viewed. For one incident in the first entity can have many relationships with the incident on the second entity, if the one incident in which two entities can have only one incident hubugan with the first entity.

Many To Many:

if any incident occurs in an entity has many relationships with other entities in the incident.

EXEMPLARY KARDINALITAS

NOTATION (E-R DIAGRAM)

Symbolic notation in the ER diagram is:

1. Rectangle represent the collective entity

2. Circle represent the attributes

3. Rhomb represent collective relationships

4. Line as the set of relations between the Association and the collective entity with entity attributes

Reference:

ER Ngurah Agus Sanjaya. Slide Part 5 - Database Dan Er-Diagram.

DATA FLOW DIAGRAM

2009-04-04T18:33:00.000-07:00

DATA FLOW DIAGRAM

Data flow diagram is also called the Data Flow Diagram (DFD).DFD function to describe the existing system or the new system will be developed without considering the logic of the physical environment where the data flows, or where data disimpan.DFD can also explain the flow of data in the system with a clearly structured.

Context Diagram

1. Consists of a process and describe the scope of a system

2. Is the highest level of the DFD that describes the entire system to input and output of the system

3. System is limited by Boundary (depicted by broken lines)

4. There may not be storage (storage)

Zero Diagram

Zero diagram is a chart that describes the process of DFD. This diagram provides a view of the overall system shows that the main function of the process or the flow of data and the external entity. At this level there is a data storage.

Detailed Diagram

Is a diagram that decipher what is the process in the diagram zero level or above.

Numbering level in the DFD:

In 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 top-level specification process . method that is used to describe the process can use a sentence with descriptive, and on a more detailed level, namely on the bottom (functional primitive) require a more structured specification, process specification will be the guidelines for a programmer to create the program.

External Entity

Unit outside is something that is outside the system, but provide data in the system or to provide data from an external system. Entity not including part of the system, the symbols with the notation.

Rules for naming:

1. The name of the form of noun

2. Terminal may not have the same name unless the object is the same

Data Flow

Data flow is the information flow is depicted with a straight line that connects the components of the system. Data flow direction is indicated with arrows and lines give the name on the flow of data flow. Flow data that flows between processes, data storage and data flow indicates that the form of data input to 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

Other provisions:

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 doesn’t need to be given a name if:

a. The flow of data simple and easy to understand

b. Describes the data flow of 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

Process

The process is what is done by the system, can process data streams or input data into output data stream. Each process has one or more inputs and produce one or more output.

Transform the process of working one or more of the input data into one or more of the output data in accordance with the desired specifications.

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 doesn’t 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, which symbol with a pair of parallel lines or two lines with one of the side open. The process can retrieve data from or provide data to the database.

Guidelines of the name:

1. The name should reflect the data.

2. When his name more than one word must be marked with the numbers.

Data Dictionary

Data Dictionary functions to help the system to interpret the application in detail and manage all elements of the data used in the system right so that the system analyst and have a basic understanding of the same input, output, storage and processing.

At analysis, 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.

Data dictionary contains the following:

1. Name of data flow: must note that readers who need further explanation about a flow of data can find it easily

2. Alias: initials or other name of the data can be written when there is

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

The 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 or levels below it. Number and the 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 input output of the flow of 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 and 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

Restrictions In DFD

1. Flow data may not be from outside the entity directly to other outside entities without going through a process

2. Flow data may not be from the savings directly to the data to outside entities without going through a process

3. Flow data may not be saving the data directly from the savings and other data without going through a process

4. Flow data from one process directly to the other without going through the process of saving data should be avoided as much as possible

Reference:

ER, Ngurah Agus Sanjaya. Slide presentation Part 4 - Data Flow Diagram.

quiz 4

2009-03-27T09:27:00.000-07:00

FIRST OBSERVATION AND ANALYSIS REQUIREMENT

Investigational System Concept

The problem is the gap in goal difference between the system and the actual system conditions.

Many reports on the detection problem may not be real,because of several things:

1. A goal that is too ideal, too difficult to achieve

2. Lack of resources and or attitude

3. Measurement system is less accurate

4. System that is the purpose behind Goal system that is out of date

5. The difference between the system and the system idel while

Problem solving:

1. Description of the condition of the system that runs through it in detail

2. Getting a consensus that the ideal system

3. Developed several alternative

4. select the best alternative

For the purpose of the investigation indicate that problems are actually happening

Constraints in the system of investigation

Investigations in several problems that often appear are:

1. Time

2. Cost

3. Knowledge

4. Politic

5. Intervention

Recommendations

Results of the investigation is a recommendation that contain, among others:

- Not to take any action because they are not finding a problem

- Perform system maintenance for a small problem.

- Improving the skills or the ability to use the system

- Consider modifications to the system in full

-Putting the problem to occur in the development plan system is carried out immediately

Investigation Tactics

Why we need tactics?

- Finding a problem for all

- Knowing for the emergence of problems

- for Determining the right solution

Investigative tactics need to be done by all elements of the system in order to receive offer solutions without disrupting their activities.

Some of the tactics that can be done:

- Listen to the user's system

- Don't give the early breakthrough

- Compare the stories of some of the user system the same case

- Note the logical inconsistency problem

Investigation Technique

Direct (internal):

1. The questionnaire

2. discussion

3. Observation

Indirect (external):

1. Flow of the procedure

2. Reviewing documents

3. Sample

4. Tabular

Current System Description

1. Inputs

2. Outputs

3. Files

4. Data elements

5. Transaction and document action volume

6. Data flow diagrams

Requirement Analysis

phase of intensive interaction between the systems analyst with the end user where the system shows the development team expertise to get feedback and trust so that the user get a good participation.

4 goals want to achieve:

1. Explain the complete system

2. Information system that describes the ideal

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

4. Providing encouragement to the user's confidence in the system development

Method Needs Analysis

1. discussion

2. Questionnaires

3. Observation

4. Procedure Analysis

5. Observation documents

Resource constraints

1. Time

2. Money

3. Expertise

4. Technology

5. External factors

Needs Analysis Document

- Analysis direction: Relationships with end users, the observation process, problems in data collection

- The user needs: The need actual, reporting requirements, training needs and the influence of the new system

- System constraints: Explain the constraints of time and cost, expertise, technology, and

-external factors

- Documents such as data collection instruments, statistical consensus, the logical flow of

-data and phisik, data elements in the initial data dictionary.

Generating Systems Alternatives

How do I approach the condition of the system at this time with the condition of the ideal system?

- Creating an alternative to solve the problem of information system

- Best alternative is applied wisely

Options Strategies

- Distributed versus centralized processing

Changes in decision-making information from the centralized data processing to the end user Decentralized responsibility center

- Integrated versus dispersed database

System designer must consider the data are entered in the data base and into the file

- Surround Strategy of System Development

About important environmental strategy in the case of company takeovers because the

information system of other companies may vary with the company at this time.

Generating Systems Alternatives

Strategy Options

Options is done before the design operational

Designing Operational Options

Options can be grouped into the design

1. Input

a. Online Vs Off Line Data Entry

b. Keyed Vs Machine Readable Data Entry

c. Centralized Vs Decentralized Data Entry

2. Processing

a. Batch Vs Realtime record update

b. Sequential Vs Direct Access to records

c. Single Vs Multiple User update of records

3. Output

a. Traditional Vs Turn Around Documents

b. Structured Vs Inquiry based reports

Selecting The Proper System

Compare tactics: systems based on the comparison of costs and benefits relative; There are 3 ways the system "A" said the system is superior to the other if :

- "A" has a cost lower than "B" and their profit same.

- "A" has a cost lower than "B" and "A" result in more profits from the "B"

- "A" and "B" have the same costs but the resulting benefit "A" more.

Several Comparative Method System

1. Break Even point Analyisis

2. Payback Period

3. Discounted PayBack period

4. Internal Rate of Return

Cost category

1. Hardware

2. Software

3. People

4. Suppliers

5. Teleccommunications

6. Physical sites

Cost details

Comparing the cost of information systems through the life of the system, analysts projected the cost changes for the future and there are 3 models cost information system, namely Linear, and exponentially Step Function.

Information system cost happen in one time and be able happen continuous.

- Cost information system that occur only once the cost ontime and development costs that occur during the development of the system.

- Cost information system that occur continuously among reccuring cost and operational cost where the cost of this is the case when the operating system information every day.

The Information System Factor

Qualitative factors that lead the performance information system that both of them:

1. Reduce errors

2. Reducing the time to fix errors

3. Reduce the response time from the workstation alternative

4. Accelerate the time of providing information

5. Improve security systems

6. Propagate update records on the source

7. Increasing user satisfaction

Company Strategy Factor

1. Customer satisfaction

2. Sales increased

3. Consumer and vendor commitment

4. Information marketing products

Representation Learning System

1. Make short presentations

2. Reduce the detail description techniques

3. represented clearly with visual tools

4. If using a model using a tool such as a laptop so that more informative

5. Emphasize the benefits of the proposed system with some alternative information that is

appropriate conditions experienced by the company.

Decision to continue or No

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

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

- Often the problem will be found with the system and the study and top management will usually ask for the re-employment system to study.

- 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.

- With the alternative, the decision to repeat a previous stage SDLC or not called Go - No-Go Decision.

Importance of developing an information system

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Importance of developing an information system

problems

By using the information system of the problems that usually can be completed with the old manual way with the information system problem is resolved more quickly. For example in the mini market, there is a cashier who has to record transactions a day with the usual manual may be slow but the results, using the information system can be done more quickly.

Irregularity in the growth of System Organization

In an organization there are certain data that must be processed, when organisai is growing data that diolahpun needed so that the larger a system is good, if not use the information system so that both orgnisasi growth will be hampered

opportunities

System information also assists in achieving opportunities. And also make it easier to seize opportunities.

directives

Informs the system can more quickly provide instruction, for example, the confusion are a company looking for a document, then the system with the information we provide live instruction to the system to search for it.

Destination development system

Development means the system can arrange a new system to replace the old system as a whole or improve the existing system. The old system need to be replaced or repaired is because some things, are as follows:

• The existence of the problems that arise in the old system. The problems that arise can be:

a. Irregularity

Irregularity in the old system caused the old system can’t operate in accordance with that expected. This irregularity may be operating inefficiently.

b. The growth of the organization

Growth of the organization must be the establishment of a new system. The growth of these organizations is the information needs of the area, the volume of data increases, changes in the new accounting principles.

• To seize opportunities

Organization began to feel that information technology should be used to improve the provision of information so that it can support in the decision making process that will be done by management. In the competitive market, speed or efficiency of the information isn’t to determine the success or strtegi plan and that plan has been developed to reach the opportunities that exist. If competitors can utilize, while the company can ‘t take advantage of this technology, the kesempatankesempatan will fall ketangan competitors.

• The instructions

Preparation of the new system can also occur because of instructions from the top leadership or from outside organizations, such as government regulations.

Expected on the new system

Has been developed with the new system, the expected increase will occur, the increase in the new system.

• Performance

Improvement of the performance of the new system which will be most effective. Performance can be measured from the throughput and response time.

• Information

Improving the quality of information presented.

• Economy

Improvement of the benefits or the benefits or a decrease in the cost-reduction.

• Control

Detect and fix errors that occur and will occur.

• Efficiency

Improvement of operational efficiency.

• Services

Improvement of the services provided by the system.

The principle of the development system

When you do the system development process, several principles must not be forgotten. These principles are as following:

• System developed for the management

After the system finished developed, which will then use information from this system is the management, so that the system must be able to support the needs that are required by management.

• The system developed is a large capital investment

System that you will develop the funds that weren’t a little. So every investment capital should consider the following 2:

a. Investigate all alternatives (minimize cost of lost opportunity)

b. Investigation must be best value: cost-benefit analysis & cost-effectivenes analysis

• System that educated people need to be developed

People involved in the development and use of this system should be the people who educated about the problems that exist and to solutions that may be made. Educated here should not mean a formal, but it can be done in the exercise work.

• Stages and work tasks that must be made in the process of system development

System development process generally involves several stages and involves the work of personnel in some form of team for it. Experience shows, without the planning and coordination work that well, then the system development process will not be successful with satisfactory.

• The development of the system doesn’t have to order

The steps that must be done doesn’t need to order, but it can be done together. For example, in the development of the system, design the output stage should be done before the design file. This does not mean that all output must be designed before they can make a new design file. But can be done simultaneously, the output during the design process is still conducted, the results of the output that has been completed can be used to design files.

• Don’t be afraid to cancel the project

For the cases a, where a project had to be stopped or canceled because it is not feasible anymore, it should be done with the firm.

• Documentation system

This documentation should be made at the time of the process of developing the system itself is still in the process. Because of this documentation can be produced from the work of each step in the development system. Documentation created and collected during the process of system development can be used for communication between the system analyst with the system and can be used to encourage the involvement of the system.

System development life cycle

Waterfall Model

Contains a series of activities such as the process has been described above and presented in a separate process, such as the requirement specification, design implementation software, testing . After each step is defined, this step in the sign off and followed the development in the next step.

The steps that are important in this model is

The analysis and specification

Services, goals and constraints resulting from consultation with users system. Then everything is made in the form that can be understood by users and staff developers.

Design systems and software

Divide the system design process needs to be system software or hardware. The process produces an overall system architecture. Design software, including the functions of system software that may be in the form of the transformation in one or more programs that can be run.

Implementation and unit testing

During this stage, the design software we realize as a complete program or program unit. Test units, including units that each test according to specification.

Integration and system testing

Unit tested and integrated the program into a complete system for menyakinkan that software requirements have been met. After testing, the system was delivered to the customer.

Operation and maintenance

This phase is long. System installed and used. Maintenance, including correction of errors not found in the previous step. Improvements to the implementation of the system and increasing service needs of the new system as found.

Iteratif Model

Step-step model Iteratif

1. Initial planning

Starting from the initial planning.

2. Planning
This stage, the stages where the plan is structured in such a way to get a system that both the good and the output

3. Requirements
Analyze user needs and the needs of the system

4. Analysis and design
In this process is conducted to analyze the process of the system will be developed and began to design the system.

5. Implementation
In this process is the system that has been created.

6. Testing
At this stage, the system will try to test, to see if in conformity with the desire.

7. Evaluation
This phase will be done from the system evaluation have been made.

Spiral model

Spiral model describes the process as a spiral which is divided into a 4 quadrant:
Processes are beriterasi according to a cycle using a prototyping approach.

• Planning
Namely the duties to plan, gather for the alternative system that will have • Risk Analysis
is to evaluate the alternatives based on the objectives and constraints. Included here to identify the risks and pastian • Engineering
That is a task that is required to build one or more representations of apikasi it. • Cusomer Evaluation.
Re-evaluate the system that was created with the customer

System development approach

• A structured approach versus classical approach (seen from the methodology used)
• Piecemeal approach versus system approach (seen from the target to be achieved)
• The bottom-up approach versus top-down approach (seen from how to determine the needs of the system)
• Total-system approach versus modular approach (seen from the way the developing)
• Great loop- approach versus evolutionary approach approach (seen from the technology that will be used)

A structured approach versus classical opponent approach

Classical approach

• Stages in SDLC-stage
• Not to include users, system analysts put more emphasis
• The problem: the development of hard, expensive treatment, the possibility of error, success is less assured, the problems in the implementation of

Structured approach

• User involvement from the beginning to determine the needs of the system
• Using tools-tools such as data flow diagrams

Piecemeal approach versus system approach

Piecemeal approach

• Emphasizing on an application or event
• Don’t override the overall target

System approach

• Viewing the system as a whole is unity
• Emphasizing the achievement of overall objectives

Bottom-up approach versus top-down approach

Bottom-up approach

• Starting from the bottom level of the operational
• It is the characteristics of classical
• Known by the term data-analysis

Top-down approach

• Starting from the top-level strategy planning
• It is the characteristics of structured
• Also known to the decision-analysis

Total-system approach versus modular approach

Total-system approach

• Develop a system simultaneously and comprehensively
• It is the characteristics of classical approach

Modular approach

• break a complex system into parts of a simple
• System to be developed on time, easy to understand and kept
• It is the characteristics of structured

Great loop- approach versus evolutionary approach approach

great-loop approach approach

• Develop a system simultaneously using the advanced technology
• At risk and spend a lot of high cost

evolutionary approach approach

• Applying advanced technology for application-specific applications
• Developed for the needs
• Save the cost and can follow the development of technology

methodology, method and algorithm

• Methodology

Is methods used in science

• method

A systematic way to grind

• algorithm

Sort-order the procedure to solve a problem

Classification of development methodology

• Functional decomposition

– Emphasizing the breakthrough system subsystem

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

• Data-oriented

– Emphasizing on the characteristics of the data processed

• Data-flow oriented: modules according to the type of data elements

• Data-structure oriented: structure of the input and output

• Prescriptive

– Usually provided by the manufacturer of the software

Tool for developing a system

• shaped graph: HIPO, SADT, Jackson’s diagram, etc.

• Tools that use the chart:

ü Activity charting : describes the activity, for example: Gant chart, flowchart, etc.

ü Layout charting: Describes the layout

ü Personal relationship charting: describes the relationship of personnel, for example: organization charts, work distribution chart

Techniques used in the development a system

• Technical project management

Technique that is used to penjadualan project, for example : CPM dan PERT

• Fack finding technique

to collect data and determine and find the facts

– interview

– Observation

• cost-benefit or cost-effectiveness analysis

• Technical meetings run

• walkthrough

System analyst & programmer

• Analyst system: study of the problems and determine the needs of the system to identify solutions.

• programmers: write a program code based on the building design is created by the analyst.

• Analysts duty system bridge the knowledge gap that occurs between the user and system programmers.

Knowledge that is required

• Technology data processing, computer programming and
• Knowledge of general business
• quantitative methods: regression, linier programming, etc.
• problem-solving expertise
• Skills of communication between personnel
• Expertise foster relationships between personnel

References

http://en.wikipedia.org/wiki/Waterfall_model

http://en.wikipedia.org/wiki/Spiral_model

Basic Concept of Information Systems Analysis and Design

2009-02-20T21:01:00.000-08:00

There are two approaching to definition of system:

1. Definition of system based on approach of procedure
According to this approach, system interpreted by as a working network from procedures which is interaction and work along to finish a specific-purpose or goal. A procedure is a correct sequences of instruction steps explaining what have to be done, who have to do, when have to be done and how to do that.

2. Definition of system based on approach of element

According to this approach the definition of system is a set of elements which is have interaction to reach specific-purpose or goal.

Characteristic system

Characteristic a system can be explained as follows:

1. Components
Consist of a number of components which interact, what each other working along to form an unity. The example is Supra System that is a larger ones system.

2. Boundary
A system has a boundary to limiting system with environmental or other system outside its.

3. Environments
Environment is a media link between a subsystem with other subsystem.

4.Interfaces
Interfaces represent link media between one subsystem with other subsystem. Passing this link enable the source of resource emit a stream of from one sub system to other sub system.

5. Input
Entered energy into system can in the form of treatment input and signal input. The treatment input is entered energy system to can walk. While signal input is energy which in process to yield output.

6. Output
The result from processed energy and classified is become an output which good for and rest of dismissal.

7. Process
Process is the change an input become output.

8. Objective/goal
A system sure have field goal or objectives. If system don't have target hence system operation there will be no use.

The Classification Of System

a. Physical system
System abstract is which in the form of idea or idea which not see itsly it system teologia.

b. Abstract system
System physical represent existing system physically, for example computer system.

c. Deterministic System

The Certain system operate with behaviour which have earned can be predicted, interaction between its sharess can be detected categorically so that its output can be forecasted. for example : Computer programe, executing precisely as according to its instruction network. System of pay, and others.

d. Probabilistic System
The System which is input and its process can be defined, but yielded output cannot be determined categorically; always there is a little mistake / deviation to forecast of the way system. for Example : marketing system.

e. Open System
The system that relation and effect external environment .This system accept input and yield output for external environment / the other sub system, so that have good operation system. This system tend to measure up to adaptation, can adapt to its environment so that can continue its.

f. Closed System
The System Physical where the process that happened do not experience of transfer of items, information or energy with environment outside system. This system work automatically without existence of interfere in of external side of it.

g. Relatively Closed System
The closed System but doesn't closed at all to accept other influences. This system in its operation can accept influence from outside which have been defined in certain boundarys.

h. Artificial System
The System imitating occurence in system. This system is formed pursuant to occurence in nature where human being unable to do it. Equally imitat exist in nature.

i. Natural System
The natural System is occurence in nature. for Example of : sea, solar system and others.

j. Human made system
Human made system is system which condition of its dicey future because containing probability element.

Information
Data is fact. Information is data that processed become better form and more meaning to accept it. If data is not useful to accept it so the data cannot be referred as by information.

Information Cycle
Data represent form which still raw which not yet earned to tell a story many, so that need processing is furthermore. Data processed to pass a model to yielded information. Data processed to yield information use certain process model.
Processed data pass a model become information, receiver later then accept the information, making a decision and conduct action, meaning to yield the other action to make a number of data return. The data will be arrested as input, in process return to pass a model and so on form a cycle.

Quality Of Information
Quality of information depended from three things, that is ;

1.Accurate
Accurate meaning information have to free from mistakes and cannot or mislead. Accurate mean information be clear express its intention.

2.Timeliness
Timeliness meaning incoming information receiver may not lose time.

3.Relevance
Information have benefit for its user.