8′th quiz

PICTURE OF ERD

Create the normalization of this ER-Diagram

First step before doing normalization, which must we do is to do un normalization of data that exist in ER-DIAGRAM. Form of un normalization table of this ER-DIAGRAM is :

After forming un normalization table, from this table we make its first normal form ( 1NF)  table. Matter which need to be done is to dissociate data to correct attribute. Its First Normal Form is :

First Normal Form ( 1NF) Table :

Second Normal Form – 2NF

After first normal Form have fulfilled, hence we make Second normal form table by doing decomposition for relationship above to become some new relationship and look for primary key from every relationship and key attribute shall be unique. From this First Normal Form Table  we earn to see that there is some candidate  key which later can become to be primary key primary among others, they are :

(NOPRO,NOBAG, NOPEG), Here are the Second Normal form :

Fd1 (NOPRO, NAPRO, LOKAPR) -> Proyek table

Fd2 (NOPEG, NAPEG, TGLLAH, KDPOS, ALM1) ->  Pegawai table

Fd3 (NOBAG, NABAG, LOKASI) -> Bagian table.

Fd4 (NOPRO, NOPEG, NAMA,JNKELT, HUBUNGAN) -> Tanggungan table.

Fd5 (NOPRO, NOPEG, JAM) -> Kerja table.

Third Normal Form – 3NF

After form 2NF have fulfilled, the next phase is create table which fulfill from 3NF. From some description that informed that 3NFnormal Form will fulfilled if form 2NF fulfilled, and otherwise there don’t non primary key attribute own depended to other non primary key attribute (depended transitive). While from tables above that fulfill to form 2NF there are some non primary key attribute which is dependence on other non primary key they are such as age attribute (“UMUR”) which is dependence on birthday attribute (” TGLLAH”) and address attribute (” ALM1″) which is dependence on  postal code attribute (” KDPOS”) so that need to normalization again become third normal form (3NF)

Pegawai table (NOPEG, NAPEG, TGLLAH, KDPOS).

Alamat table(DPOS,ALM1)

UMUR table(TGLLAH,UMUR)

7′th quiz

NORMALIZATION

Design Process of Database ( review)

Collecting requirement of user/business

Developing E-R Model pursuant to requirement of user / business

Converting E-R Model to relationship gathering ( tables)

normalizing the Relation to eliminate the anomaly

Implement to database by making table to each relationship which have normalization.

NORMALIZATION OF DATABASE

Normalization is process forming of data bases structure so that most ambiguity can be eliminated

Normalization Phase started from lightest phase (1NF) tightest till ( 5NF)

Usually only coming up with level 3NF or BCNF because of have enough adequate to make goodness quality tables.

The normalization have to done because of :

Optimalizing Structures of tables

Improving speed

Eliminating inclusion of same data

More efficient in usage of storage media

Lessening redundant ion

Avoiding anomaly ( anomalies insertion, anomalies deletion, update anomalies). improved Data integrity

A tables told by good ( efficient) or normal if fulfilling 3 criterion such as:

If there is decomposition ( elaboration) of tables, hence its decomposition have to be secured ( Lossless-Join Decomposition). Its Meaning, after the tables elaborated / decomposed become new tables, the new tables can yield initially tables with precisely

The looked after of depended functional at the time of change of data ( Dependency Preservation)

not impinge Boyce-Code Normal Form ( BCNF)

If the third criterion ( BCNF) cannot fulfilled, hence at least the tables not impinge Normal Form of third phase ( 3rd of Normal Form / 3NF )

Functional Dependency

Functional Dependency depict relation of attributes in a relationship

An attribute told by functionally dependant at other if us use that attribute value to determine other attribute value

Symbol which is used is for representing dependency functional. read as functionally determine

Notasi: A -> B

A and b is attribute of one table. Matter functionally A determines b or b cling to, if and only if available 2 data row with appreciative A same, therefore point b also with

Notasi: A -> B atau A x -> B

Are opposite of previous notation.

First Normal Form – 1NF

A[N tables told as reside in I normal form if it not reside in unnormalized table form, where duplication of a kind of field happened and enabled there is null ( empty ) field

There are may not existence of :

Many valuable attribute (Multi valued Attribute).

Composite Attribute or combination from both.

so:

Price of Domain attribute have to represent atomic price

For example College Student Data as follows:

can be decomposing become:

collage table

Second Normal Form - 2NF

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

A tables not fulfill the 2NF, if there is depended attribute ( Functional Dependency) only having the character just partial ( only depend on some of primary key)

If there are attribute which not have depended to primary key , hence the attribute have to be moved or eliminated

functional Depended of X -> Y told by full if deleting an attribute of A from X its mean Y shall no longer depend on functional

functional Depended of X -> Y told by partial if vanishing a[n attribute of A from X mean Y still depend functional

Relationship scheme of R in form of 2NF if each attribute non primary key A ? R hinge full by functional at primary key R

following Tables is fulfill on 1NF, but not including as 2NF

not fulfill on 2NF, because { NIM, Kodemk} considered to be primary key while:

{ NIM, Kodemk } -> Namamhs

{ NIM, Kodemk } -> Alamat (Address)

{ NIM, Kodemk ) -> Matakuliah

{ NIM, Kodemk } -> Sks

{ NIM, Kodemk } -> Nilaihuruf

The Tables require to decomposed become some tables which is fulfill on 2NF standard.

Its Functional acre dependency:

{ NIM, Kodemk -> Nilaihuruf ( fd1)

NIM -> { Namamhs, Address} ( fd2)

Kodemk -> { Matakuliah, Sks} ( fd3)

So that :

fd1 ( NIM, Kodemk, Nilaihuruf} -> Tables of Value

fd2 ( NIM, Namamhs, Address} -> Tables of Student

fd3 ( Kodemk, Matakuliah, Sks} -> Tables of Matakuliah

Third Normal Form - 3NF

Normal 3NF form fulfilled if have fulfilled 2NF form, and otherwise there is non primary key attribute which is owning depended to other non primary key attribute ( transitive depended).

Example :

following Tables of collage student fulfilled to 2NF standar, but not fulfilled on 3NF

Because of there are non-primary key attribute (Kota and Provinsi), which is has a dependence on the other non-primary key attributes (KodePos):
KodePos -> {Kota,Provinsi}

So that the table need to decompositing to be:

· Student (NIM, NamaMhs, Road, KodePos)
KodePos (KodePos, Province, City)

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 first Normal and each attributes forced to depends on the function in the super key attributes.
In the following example there is a “seminar” relationship, and the Primary Key is NPM + Seminar.
Students may take one or two seminars. Each seminar requires 2 counselors and each students teach by one of the 2 counselors of seminar. Each counselor can only take one seminar course. In this example NPM and seminar show a Counsellor.

Boyce-Codd Normal Form (BNCF)

Seminar Relationship form is third Normal form, but didn’t BCNF
because seminar Code is still hinge with function on Counselor, if each Counselor can teach just one seminar. Seminar dependent on one attribute which is not super key that likes BCNF standards. Therefore
seminar relationship shall be broken down as two such as:

The Fourth and Fifth of Normal Form

The relations can become fourth normal form (NF 4) if the relations in BCNF and didn’t contain dependence with 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 has many relationship value.
The relations in fifth normal form (5NF) deal with the property called the join without any loss of information (lossless join). Fifth normal form (5 NF also called the PJNF (projection join normal form). This case is very appear less and difficult to detect practicely.

6′st Quiz

DATABASE AND ER-DIAGRAM

Database Definition

A group of data which is saved in magnetic disk, optical disk or other secondary depository·
Inwrought collection of data which is interconnected between each other from enterprise ( company, governmental institution or private sector )
For example:

• Manufacture company >>> data of production planning, data of actual produce, data of ordering material, etc
• Hospital >>> patient data, doctor, nurse, etc

DATABASE MANAGEMENT SYSTEM

• database Corps / database alliance with application software which is based on database
• This application programs are used to access and look after database
• Especial target of DBMS is to provide an efficient and easy environment for the usage, withdrawal and depository of information and data

BIT, BYTE, FIELD

Beet >> representing part of smallest data which is contain value 0 or 1

Byte >> corps of a kind of beets

Field >> a group of a kind of bytes, in database using attribute term

ATTRIBUTE / FIELD

• Representing the nature or characteristic from an entity which is providing detail of clarification about that entity
• A relationship also can having an attribute

ATRIBUTE TYPES

Single Vs multi value

• Single >> can only fill at most one value
• Multi value >> can fill my more than one value with same type

Atomic Vs composition

• Atomic >> indiscrete into smaller attribute
• Composition >> representing alliance of some smaller attribute

Derived Attribute

• Attribute which is its value can be conducted from other attribute value, for example >> age which is conducted by birthday attribute

Null Value Attribute

Attribute which is not has value to record

Mandatory Value Attribute

Attribute which must has value

RECORD

Record represent a data line in a relationship

Record consist of a corps of attributes which is interacted to give information about entity / relationship completely

ENTITY / file

File represent corps of a kind of record and has same element, attribute is same but its data value different each other

Type File

In application processing, file can be categorized:

• Mains file
• Transaction File
• Report File
• Activity File; etc

DOMAIN

Domain represents corps of values which is enabled to stay in one or more attribute. Each attribute in a relational data bases defined as a domain

KEY OF DATA ELEMENT

Key is element of record which is used to find the record when accessing or also can used to identify each entity / record / Line

TYPES OF KEY

Super key represent one or more attribute from a tables which is able to be used to identify entity / record of tables uniquely ( not all of attribute can become super key)

Candidate Key is super key with minimum attribute. Candidate Key may not contain attribute of other tables so that candidate key beyond super key but of course not yet on contrary.

Primary Key is one of the attribute of candidate key can be selected /determined to become primary key with three criterions:

1. The Key more natural to be used as reference 2. The Key more simple 3. The unique of Key have to guaranteed.

Alternate Key is attribute of candidate key which is not chosen become primary key.

Foreign Key represent any attribute subjecting to primary key at other tables. Foreign Key will happened in relationship which is has cardinality one to many or many to many. Foreign Key usually is always put down at tables which is flange to many.

External Key represent a lexical attribute ( or gathering of lexical attribute) which is its values always identify one instance object.

ERD (ENTITY RELATIONSHIP DIAGRAM)

ERD is a network model which is using word formation which is kept abstractly in system.

Difference between DFD and of ERD:

• DFD represent a function network model which is to be executed by system
• ERD represent data network model which is emphasizing at structure and data relationship

ELEMENTS OF ERD

Entity

At ER Diagram. Entity depicted with rectangle. Entity is something that there is in real system and also abstraction where data saved or where data exist.

Relationship

At ER Diagram relationship can be depicted with a rhomb. Relationship is natural relation that happened between entity. In general it called with elementary vb. so make it easy to read its relationship.

Relationship Degree

is amount of entity that participating in one relationship. The degree which is often used in ERD.

Attribute

is the nature or characteristic of each entity and also relationship

Cardinality

show optimum of record which is able to make a relationship with entity at other entity

Relationship Degree

Unary Relationship

is model of relationship that happened between entity coming from same set of entity .

Binary Relationship

is model of relationship that happened 2 entity.

Ternary Relationship

representing relationship among 3 type of entity unilaterally.

CARDINALITY

There are 3 relationship cardinality that is

One to One :Level of Relation one to one expressed with one occurrence at first entity, only having one relation with one occurrence at second entity.

One To Many or Many to One :Level of Relation one to many is equal to many to one .For one occurrence at first entity can have many relation with occurrence at second entity, if on the contrary one occurrence at second entity only can has relation with one occurrence at first entities.

Many To Many : happened if each occurrence at an entity has many relation with occurrence at other entity

NOTATION OF ER DIAGRAM

Symbolic notation in diagram of ER are:

rectangle express gathering of entities

Radian express attribute

Rhombic express relationship gathering

lines as link between with gathering of relationship with Gathering of Entity and gathering of entity with its attribute

5′th quiz

DATA FLOW DIAGRAM

DFD is often used to develop a system or new system which developed logically without considering physical environment where data is streamed

DFD represent tool that used appliance at methodologies of structural system development

Data Flow Diagram

• Depicting the division of system into smaller module
• Facilitating user who has less knowledge about computer area to understand system which to be done.

Context Diagram

• Consist of one process and depict scope from a system
• Representing highest level of DFD which is depicting all of input to system and output form system
• System limited by boundary ( depicted by dash line)
• There may not be any is depository ( storage)

Zero Diagrams

• Depicting process of DFD
• Giving view by totally about system which is handled, showing existing especial process or function, data stream and of external entity
• At this level is enabled by the existence of data storage For process which is not detailed again in the next level so enhanced by symbol ‘*’ or ‘ P’ at the end of process number
• Balance of Input and output ( balancing) between diagram 0 with context diagram have to be looked after

Detailed Diagram

• Representing diagram which is elaborating the process which is in zero diagram or level above it
• In one level there are shall not more than 7 process and maximal 9, if more, then decompositions must be done

Process Specification

• Every process in DFD must have the specification of process
• At top level method that used to depict process can using descriptive sentence
• At more detailed level, at most under of process ( primitive functional) need more structural specification
• Specification of process will become guidance to programmer in making program ( coding )
• Method which is used in specification of process: breakdown of process in form of story, decision table , decision tree

External Unity

• Something that beyond of system, but it give data into system or give data from system
• Symbols by notation box
• External entity is not the part of system
• Naming:

· Name of terminal in form of noun

· Terminal may not have same name except its object are same object

Data Flow

• Representing place where is information is streaming
• Depicted with straight line which is connecting component of system
• Data flow shown with line and direction bow get named by data flow which is streaming
• Data flow streamed among process, data storage and show data flow from data which is in form input for system.
• Guidance of giving a name:

· Name of data stream which is consist of some stream word related by continued line

· There may not any data stream that its name are same and name that was given have to express its contents

· Data stream which is consist of some element can be expressed with group of element

· Avoid to use word ‘ data’ and ‘ information’ to give a name of data stream

· Laboring to data name of data stream completely written

• Other rule:

· Name of data stream which is come into a process may not equal with name of data stream which is out from it process

· data Flow which is into or go out from data of storage didn’t need be named when :

· Data stream is comprehended easy and simple

· Data stream depict all of data item

· There may not be any data stream from terminal to data storage or on the contrary because terminal isn’t part of system, relation between terminal with data storage have to through a process

Process

A process is activity or job by people, computer or machine from result of a data flow which enter into process.

• Process represent what is system done
• Process can processing data stream or data input to become output data stream
• Function of process are to transforming one or more data input to become one or more output data according to specification which is wanted
• Each process have one or some input and also yield one or some output
• Process often also called as bubble
• Guidance to giving process name:

· Name of process consist of noun and verb which is expressing function of that process

· Don’t use word “process” as part of the name of a bubble

· There are may not any some process which have same name

· Process has to numbered. Number sequence as possible follow process sequence or stream, but that way number sequence didn’t mean absolutely represent sequence of process chronology

Data Storage

• Data storage represent place to data repository in system
• A couple of parallel line or two line which is one side of it is openly is symbol of data storage
• Process can take data from or give data to database
• Guidance to giving name:

· Name have to express data storage

· When its name more than one word so have to addicting with continuous line

Data Dictionary

• Data Storage assist perpetrator of system to interpret application detailed and organizational all of data element which is used precisely by system so that user and system analyst have same idea about input, output, storage and process
• At analysis phase, data dictionary used as communication tool among system analyst and user
• At phase of scheming system, data dictionary used to designing input, database and report
• The character of data flow at DAD is global, more detailed information can be seen at data dictionary
• Data dictionary load the followings:

· Name of data flow: have to be noted so reader need more clarification about a data flow can look for it easily

· Alias: other name or alias of data can be written if it has

· Data form: used to grouping the data dictionary into its use when system scheming

· Data flow: showing where is data streaming from and where data to go

• Clarification: giving clarification about meaning of data flow

Balancing on DFD

• Data stream which come into and go out from one process have to equal to data stream which come into and go out from detail of process at level under it
• Name of data stream which come into and go out from one process have to equal to name of data stream which enter into and go out from detail of process
• Amount and name of external entities from a process have to equal to name and amount of external entities from detail of process
• Something which must be gave attention to DFD which is has more than one level:
• Input and output between one level and next level Have to balance
• The balance between level 0 and level 1 seen at input / output of data stream into or from terminal at level 0, while balance between level 1 and level 2 seen at input / output from data stream into / from pertinent process
• Name of data stream, data storage and terminal at every level have to be same if its object are same

Prohibition in DFD

• Data flow may not from directly external entity go to other external entity without passing a process
• Data flow may not from directly data deposit go to external entity without passing a process
• Data flow may not from directly data deposit go to the other data deposit without passing a process
• Data flow from one directly process goes to other process without passing data deposit may better as possible avoided.

4′th quiz

FIRST OBSERVATION AND ANALYSIS REQUIREMENT

1. CONCEPT OF INVESTIGATION SYSTEM

· Basically investigation system happened because there is a difference between the real condition of system purposes and condition.

· Problem detection report which is not really occur because of;

· The target too ideal.

· Lack of resources and attitude

· Measurement of system is not too accurate.

· Target of system which is not up-to-date.

· Difference between ideal system and temporary system.

· Problem solving:

· Formulation of system which is working à investigation in detail.

· Getting ideal system consensus.

· Developing some alternative

· Choosing the best alternative.

· The purpose of investigation in to show the problem which is really happened.

2. CONSTRAINT IN THE INVESTIGATION SYSTEM

In doing the investigation, we usually faced with some constraint in its applying. The constraints which often emerge in conducting the investigation are:

· The limitation of time

· Limitation of expense

· Sciences

· Political

· Interferences

3 . RECOMMENDATION

we always get result Each time we do investigation, the Result of a investigation that contain, such as:

· Do not take any action à did not found any problem

· Doing system conservancy à small problems

· Improving ability or skill of the user

· Considering total modification system

· Placing the problem that happened into system development plan which is immediately done.

4. TACTIC OF INVESTIGATION

In order to do the investigation, of course we need some certain tactics, the Reason why we need some tactics in investigation are:

· To Find all problem

· knowing the cause of the problems that appear

· To Determine a correct solution

Tactics is also done so that all system elements can accept solution offer without bothering their activity.

5. TECHNIQUE OF INVESTIGATION

Besides tactics, in order to do the investigation, there are 2 techniques that be able to do such as

· Direct Investigation:

· Questioner

· Question and answer

· Perception

· Indirect Investigation:

· Procedural stream

· Document study

· Sample

· Tabular

6. SYSTEM DESCRIPTION IN THIS TIME

· Input

· Output

· File

· Data element

· Transaction volume and action document

· Data flow diagram

7. REQUIREMENT OF ANALYSIS

intensive Interaction phase among system analyst with end user where the system development team show their membership to get comments and trust of the user so that they get good participation.

4 TARGET OF WHICH WISH TO BE REACHED

· Explaining system completely

· Depicting ideal information system

· Bringing ideal information system to condition in this time by paying attention resource constraint

· Giving motivation to confidence the user into the system development

Method

· Questioner

· Question and answer

· Observation

· Document study

· Analysis Procedural

Resources Constraint

· Time

· Money

· Membership

· Technology

· External Factors

Document Requirement of Analysis

· analysis Instruction : Relation with end user, perception of process, problem in order to collecting data

· Requirement of User : Requirement in fact, Requirement of report, requirement of training and new system influence

· System Constraint : Explaining time constraint and expense, membership, technological and factor of external

· Document in the form of data collecting instrument, statistical consensus, data stream by logical and physical, early data element in data dictionary.

8. GENERATING SYSTEMS ALTERNATIVES

How to close up the system condition at this moment to ideal condition system?

· Create alternative to solve the information system problem

· Best alternative will applied accordance with wisely

Strategy selection

· Distributed versus centralized processing

The change of information decision from centralized data processing to decentralized end user responsibility center.

· Integrated versus dispersed database

Designer of system have to consider to any kind of data which enter into database and which come into File

· Surround Strategy of System Development

Environment around the strategy are important in case to overtake company because information system from other company might possible different with company at this moment.

Tactic Selection

Tactic selection have been Done before operational planner selection started. If we can make some tactic before doing operational planner, we can choose the best tactic to solve the problem.

Operational scheme Choice

Scheme choice may able categorize into :

· Input

§ Online Vs Off Line Data Entry

§ Keyed Vs Machine Readable Data Entry

§ Centralized Vs Decentralized Data Entry

· Processing

§ Batch Vs Realtime record update

§ Sequential Vs Direct Access to records

§ Single Vs Multiple User update of records

· Output

§ Traditional Vs Turn Around Documents

§ Structured Vs Inquiry based reports

9. SELECTING PROPER SYSTEM

Equal tactic: equivalent system based on cost and profit relatively. There is 3 system, A called more excellent between other system if:

· Have low cost then B and their profit same.

· A have low cost then B and A produce profit more than B.

· A and B have same cost but produce of profit A more than B.

Several comparative method systems

· Break Even point analysis

· Payback period

· Discounted payback period

· Internal rate of return

Cost category

· Hardware

· Software

· People

· Suppliers

· Telecommunications

· Physical sites

Cost details

Equal system information cost by means of life system, analyst projection several cost change for future and 3 cost model information system that is Linear, Exponential and Step Function.

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

· Information system cost happening in one time that is on-time cost and development cost while system development consist.

· Information system cost happening continuous there are recurring cost with operational cost while cost happen at information system operated every day.

10. FACTOR OF INFORMATION SYSTEM

Qualitative factor direct to best information system there are:

· reduce mistake state

· reduce time to solve mistake

· reduce perceptive time from alternative workstation

· increase time to supplying information

· raise system security

· increase update from active record

· raise user satisfied

Company Strategy Factor

· User satisfied

· Improvement of selling state

· Commitment between consumer and vendor

· Information product marketing

1          11. PRESENTATING STUDY OF SYSTEM

· Do shortly presentation

· reduce details clarification technique

· represented clearly with visual tools

· if use model, use tools like laptop to make more informative

· Emphasizing advantage of proposal of information system with some alternative with company condition

12.   DECISION TO CONTINUE OR NOT

· If company set mind to develop system so hereinafter information department will process, that is Process of Design System

· If on the contrary so System Development Life Cycle ( SDLC) will be discontinued

· Frequently, the problem will be found with learn system and usually top management will ask to reworking for learn system

· A model will explain some part of step that is repeated and sometime information department will make a decision to repeat step before explaining learn system

· With alternative, decision to repeat a step of previous SDLC or not called Go – No – Go Decision

Information Systems Analysis and Design Part-2

the importance of developing an information system

Development of system mean: to compile a new system to replace system old ones, or improve the old system. Something causing the system requires to be improved are:

· Existence of Problems (problems)

· Annoyance in Growth’s system Of Organization

· To Reach for opportunities (opportunities)

· Existence of instructions (directives)

the purpose or goal of developing an information system

To solving the problems

Reach for opportunities

Fulfilling given instruction

organization’s expectations after implementing an information system are :

· Performance: performance of system developed cans more mounting so that become more effective. This can be measured with throughput (amount of work of which is it can done in one moment) and its response.

· Information: make-up of quality to presented information.

· Economy: make-up of advantage or benefit or decreasing cost that happened.

· Control: make-up of operation to detect and improve mistake and also insincerity that would be happened.

· Efficiency: make-up of to operation efficiencies. Efficiencies relate to how the resource used by reckoning lowest expenditure.

· Services: make-up of to service given by system

the principles of developing an information system

· System which is developed is management

· System which is developed is big capital investment

· developed System need one who is have education

· Step of work and duty which must be conduct in course of developing system

· The process to developing system didn’t have to be successive

· Don’t fear about to canceling a project

· Documentation existence for guide in system development.

three system development life cycle models

Systems Development Life Cycle

The Systems Development Life Cycle (SDLC) is a conceptual model which used in project management that describes the stages involved in an information system development project from an initial feasibility study through maintenance of the completed application. Various SDLC methodologies have been developed to guide the processes involved including the waterfall model (the original SDLC method), iterative model and the spiral model.

1. Waterfall model

The image below is the classic Waterfall model methodology, which is the first SDLC method and describes the various phases involved in development.

Briefly on different Phases:

Requirement Analysis and Design

Analysis gathers the requirements for the system. This stage includes a detailed study of the business needs of the organization. Options for changing the business process may be considered. Design focuses on high level design like, what programs are needed and how are they going to interact, low-level design (how the individual programs are going to work), interface design (what are the interfaces going to look like) and data design (what data will be required).

Design

System design functions and operations are described in detail, including screen layouts, business rules, process diagrams and other documentation. The output of this stage will describe the new system as a collection of modules or subsystems.

Implementation

In this phase the designs would be translated into code. Computer programs are write it using a conventional programming language or an application generator

Testing

In this phase the system will be tested until its work . Normally programs are written as a series of individual modules, these subjects to separate and detailed test.

Maintenance

Inevitably the system will need maintenance. Software will definitely undergo change once it is delivered to the customer.the Change could happen because of some unexpected input values into the system. In addition, the changes in the system could directly affect the software operations.

2. iterative model

In software development, iterative is used to describe a heuristic planning and development process where an application is developed in small sections called iterations. Each iteration is reviewed and critiqued by the software team and potential end-user insights gained from the critique of iteration are used to determine the next step in development. Data models or sequence diagrams, which are often used to map out iterations, keep track of what has been tried, approved, or discarded, and eventually serve as a kind of blueprint for the final product.

3. Spiral model

The spiral model, also known as the spiral lifecycle model, is a systems development lifecycle (SDLC) model used in information technology (IT). This model of development combines the features of the prototyping model and the waterfall model. The spiral model is favored for large, expensive, and complicated projects.

The steps in the spiral model can be generalized as follows:

1. The new system requirements are defined in as much detail as possible. This usually involves interviewing a number of users representing all the external or internal users and other aspects of the existing system.

2. A preliminary design is created for the new system.

3. A first prototype of the new system is constructed from the preliminary design. This is usually a scaled-down system, and represents an approximation of the characteristics of the final product.

4. A second prototype is evolved by a fourfold procedure:

1. evaluating the first prototype in terms of its strengths, weaknesses, and risks;

2. defining the requirements of the second prototype;

3. planning and designing the second prototype;

4. constructing and testing the second prototype.

5. At the customer’s option, the entire project can be aborted if the risk is deemed too great. Risk factors might involve development cost overruns, operating-cost miscalculation, or any other factor that could, in the customer’s judgment, result in a less-than-satisfactory final product.

6. The existing prototype is evaluated in the same manner as was the previous prototype, and, if necessary, another prototype is developed from it according to the fourfold procedure outlined above.

7. The preceding steps are iterated until the customer is satisfied that the refined prototype represents the final product desired.

8. The final system is constructed, based on the refined prototype.

9. The final system is thoroughly evaluated and tested. Routine maintenance is carried out on a continuing basis to prevent large-scale failures and to minimize downtime.

Approaches of developing a system

There are several approach to developing a system, that is:

· Classic approach vs. structured approach

Classic approach is approach inside of developing a system that follow stages at system life cycle without supplied with tools and techniques.
Troubleshoots which can arise from this approach, such as:

1. Difficult development.
Classic approach less give tools and techniques insides develop system and finally software development process becoming not directional and difficult to be done by programmer.

2. Treatment cost or system maintenance will be more expensive.
The expensive treatment cost at classic approach caused system documentation that developed less complete and less structured.

3. Possibility of big error.
This approach doesn’t prepare to manner systems analysis to do system testing, so that system errors possibility will be bigger.

4. System achievement less well guaranteed.
Because classic approach less involve system user in system development, so system user needs are less matching with the one which desirable and as finally system that applied less success.

5. Applying internal issue.
User will be startled and unaccustomed with new system suddenly introduced.

Structured approach equipped with tools and techniques that wanted in system development, so that the end result from system which developed be got system the structure will be defined well and clear. In this approach, consumer involve from early to determine requirement of system and using tools like data of flow diagram

· Piecemeal approach vs. system approach

Piecemeal approach is system approach development that emphasized at one particular activity or certain application. This approach don’t heed overall target.

System approach pays information system as integration unitary to each activity or the application. This approach also emphasized in overall goal achievement from organization, not only in that information target.

· Approach of bottom-up vs. approach of up-down

Bottom-Up Approach is begin from level under organization, that is from formulation requirements to handle transaction and climb level on with formulate information need based on transaction. Bottom-up approach is used in systems analysis steps, because of the pressure is data that be cultivated before, information that be produced will follow the data. Up-Down Approach on the contrary with bottom-up approach, this approach is begin from level up organization, that is begun with define target and organization policy. Step furthermore from this approach information need analysis. After information is determined, so process goes to transaction processing, that is determination output, input, data base, operating procedure and control. This approach be feature from structured approach. Top-down approach when used in systems analysis stage called also with term decision analysis, because that be pressure information that wanted for decision making by management beforehand, then data necessary cultivated to defined to follow information that wanted.

· Total-system approach vs. modular approach

Total-system approach to be approach develops system together according to comprehensive. This approach less synchronized for complex system, because will be difficult be developed. This approach be feature classic approaches.
Modular Approach tries to divide complex system to simple some part, so that system easier will be understood and developed. Furthermore consequence system can be developed of time that planned, easy understood by system user and easy to maintain. This approach be feature structured approaches.

· great-loop approach vs. evolutionary approach

Great-loop approach applies change comprehensive according to together use sophisticated technology. This change contains many risks, because computer technology so great-loop. This approach also too expensive, because need investment at the same moment for all technology that used and difficult to developed because too complex. Evolutionary approach apply sophisticated technology just for applications that need that moment and then be developed for periods next based on technology development. This approach causes investment not too expensive and can follow fast technology development.

Meaning of methodology, method and algorithm

Methodologies: unity of method, procedure, conception work, postulate or the order which is used in a science, artistic and or discipline. Method: systematic technique to do something. Algorithm: sequential Procedure to solve a problem

The three classifications of development methodology

There are three classifications of developing a system, they are :

• Functional decomposition

Functional decomposition is emphasizing system which resolving becomes subsystem. For examples :HIPO, Stepwise refinement.

• Data-oriented

Data-oriented is emphasizing on processed data characteristic.

• Flow oriented data: types appropriate modules data elements

• Structure oriented data: input structure and output

• Prescriptive

Usually provided by software maker factory.

Tools for developing a system

Get graph form: HIPO, SADT, Jackson’s diagrams, etc.

Tool that utilizes to design are:

· Activity charting: figuring activity, example: chart’s substituting, flowchart, etc.

· Layout charting: figuring layout

· Personal relationship charting: figuring person relationship, example: organization chart, working distribution chart

Techniques used in developing a system

There are techniques which used in order to developing a system, they are:

· analysis’s tech cost / benefit à cost benefit and cost effectiveness analysis

· Tech finds fact à this technique used to gather and determines data / fact

· Interview

· Observation

· Project management techniques à this technique used to scheduling project, for example: CPM and PERT

· Going tech shuts close

· Inspection tech

the differences of being a system analyst and a programmer and also mention what are the knowledge a system analyst should posses

Who Analysis System And Programmer are ?

The Analysis system is people who study about analyzing system and identifying problems and determine system which user needs

Programmer is people who write program’s code to create an application which it based on has planned to get up by system analyst.
Function and or task from a analyst system that is as mediator or liaison between system user with programmer. Analyst system must realize right second knowledge differ about the computer technology to can communicate with programmer and knowledge about application that be developed so that can communicate with system user.

Knowledge And Skill That must Need by System Analyst
Found several vast eruditions and skill that must has by a system analyst, that is:

1. Knowledge and skill about data processing technique, computer technology and computer programming.
Technical skill that must has belonged skill in using tool and technique for application software development with skill in using computer.
Technical knowledge that must be has by system analyst are erudition about hardware, data communication technology, computer languages, os, utilities, and another.

2. Knowledge about business for general.
This knowledge be wanted so that system analyst can communicate with system user

3. Skill builds connection delivers staff.
Human is critical factor insides system and one of human character with another differ, so that need a skill to build connection delivers staff

4. Trouble-shooting skill.
System analyst must has ability to put complex troubleshoots which is faced by business, divide problem into parts, analyze and then must can returning composed to be a system can overcome troubleshoots.

5. Knowledge about quantitative method.
System analyst use many quantitative methods in build an application models, like dynamic programming, regression, network, decision tree, trend, simulation and other like it.

6. Communication skill delivers staff.
System analyst must has an ability to hold communication either through tongue or article. This skill is need in interview, presentation, meeting and report maker.

ADSI

System Based Concept

There are 2 kind of approached to definite a system :

1. System approached by procedure

System is network group of procedures which is has an interaction, gathering with to do an activity or finishing certainly target.

Procedure is a sequenced clerical operation, which is involve some people in one or more departmental, which used to guarantee a same handling of business transaction that happened.

2. System approached by component or element

system is corps of elements which is have interaction to reach specific-purpose.

A system has an intention and it used to getting a goal or getting an objectives.

1. System Characteristics

A system has characteristics such as:

1. Components

2. Boundary

3. Environment

4. Interface

5. Input

6. Output

7. Process

8. Objectives or Goal

1. System component

System consist of some component which has been interacted, that mean they work together to make a unity. System components or system elements may be able to be in form of subsystems or part of the system. Every subsystem has nature of the system to running a function and influences all of the system process.

2. Boundary

system boundary represent an area that limiting between a system with other system. These system boundaries enable a system viewed as one system.

3. Environment

External environment of system is any beyond the bounds of system which can influence the system operation. External environment of system can profit this system and also can harming the system.

4. Interface

Interfaces represent link media between one subsystem with the other subsystem. By passing this interface, resources enable to float from one subsystem to other subsystem. output of subsystem can become to be input of other subsystem.

5. Input System

Input is energy which putted into the system. Input can be in form of maintenance input and signal input. Maintenance input is energy insert into so that system can operate. Signal input is energy that processed to get output.

6. Output System

Output is result of energy that cultivated and classified to be useful output and exile remainder. Output can be input for other subsystem or to supra system.

7. System Process

A system may have a processing part that will change input come to be output.

8. System Objectives or Goal

A system must has goal and objectives. Target of the system is very determine once input that wanted by system and the output that will be produced by system.

2. System Classification

System can classified from several view point, that is:

1. System classified as abstract system and physical system.

Abstract system is system which can be in form of brain or ideas which physically didn’t appear.

Physical system is a system that physically exists.

2. System classified as natural system and human made system.

Natural system is system that came from naturally process, it isn’t made by human.

Human made system is system which is designed by human. Human made system involves interaction between human and mechine called human-machine system or also called man-machine system.

3. System classified as deterministic system and probabilistic system.

Deterministic system operated with behavior which can be predicted. Interaction between its parts can be detected categorically, so the output of system predictable.

Probabilistic system is system which is its future condition can’t be predicted because of contain probability element.

4. System classified as closed system and open system.

Closed system is system not connected and not influenced by environment. Theoretically this closed system is exist, but in reality there is no system is really closed, only exist is relatively closed system.

Open system is system which related and influenced by external environment. This system get input and produce output for outside environment or the other subsystem.

Information Based Concept

Information means data that cultivated to be more useful form and more values for its receiver. The recources of Information is data. Data means plural form from a single data item. Data is real thing which show events. Event means something happen in a time.

1. The Cycle of Information

Data means the raw form of something which can’t tell us about the information inside, so it needs to process continued. Data processed pass through from a model to resulting information and then it receive by receiver and make decision and do something, it mean resulting another movement that will be make the data is back. That data would be caught as input, it processed again from a model, it work continue until the process become a cycle. This cycle by John Burch called information cycle. This also called data processing cycles.

2. The Quality of Information

The quality of quality information depends of three things, such as accurate, timeliness, and relevance.

· Accurate, the information must be free from errors and not refraction or mislead.

· Timeliness, it mean the information may not be late. The expired information will not have a value, because information is a basic to get a decision.

· Relevance, it mean the information have a benefit for the user. The relevance information for every people with the other one is different.

3. The Value of Information

Value of information depends of two things, such as benefit and cost to reach it. An information called values when the benefit more effective than the cost to reach.

Information System Based Concept

Information system mean a system in an organization which meet daily process transaction requirement, to support operation, managerially and activity of strategy from an organization and serve certain external side with needed reports.