SYSTEM CONCEPT INVESTIGATES
1. Difference distinctive (gap) among system aim and condition of system actually
2. Reporting detects problem not quite a reality
* To the effect over ideal
* Lack for resource and or attitude
* System measurement less accurate
* To the effect system already is behind in
* The difference among idel's system and temporary system
3. Problem solving:
* System formulation that be walks → rinci's ala investigation
* Getting ideal system consensus
* Develop severally alternative
* Choosing the best one alternative
4. To the effect investigation → pointing out problem that actually happens
CONSTRAINT IN SYSTEM INVESTIGATES
1. In do investigation some constraint which often emerges is:
* Time
* Cost
* Scholarship
* Politics
* Interference
RECOMMENDATION
1. Result of investigation is one recommendation which contain for example as follows:
* Don't take action whatever → problem undiscovered
* Doing system preserve → little problem
* Increasing ability or user skill
* Regarding system modification totally
* Placing happening problem into systems developmental plan which shortly be done
TACTICS INVESTIGATES
1. Why needs tactics?
* Find all problem
* Knowing its appearance cause problem
* Determining solution in point
2. Done so all system element can accept solution offer without trouble their activity
3. Severally tactics which can be done:
* Listening system agent opinion
* Don't give startup resolving
* Comparing story some bodies system agent to same case
* Inkonsistensi logikal's problem looking at
4. Tactics investigates to exist two tricks which is :
Directly :
* Kuesioner
* Question-answer
* Watch
Indirect :
* Procedural flow
* Studying document
* Sample
* Tabular
CURRENT SYSTEM DESCRIPTION
1. Entry
2. Output
4. File
5. Data element
6. Transactions volume and action document
7. Data flow chart
ANALISIS'S REQUIREMENT
Intensive interaction phase among system analyst with end user where systems developmental team point out its membership to get comment and user trust so gets good participation.
4 AIM THAT WANT TO BE REACHED :
* Wording comprehensive system
* Figuring ideal information system
* Taking in ideal information system to condition of currently by notices resource constraint
* Giving push to wearing confidence into developmental system
Method
* Question-answer
* Kuisioner
* Observation
* Analisis's procedure
* Document watch
RESOURCE CONSTRAINT
* Time
* Money
* Membership
* Technology
* External factor
Document is analisis the need
* Analisis's instruction: Relationship with end user, watch processes, about problem in data collecting
* Wearing requirement: Real requirement, Write-up requirement, training requirement and new system influence
* System constraint: Wording time and cost constraint, membership, technology and external factor
* Document as instrumental as data collecting, statistical consensus, ala data flow logikal and physical, early data element in lexical data.
GENERATING SYSTEMS ALTERNATIVES
How to near current system condition with condition of system which ideal?
Making alternative to solve information system problem
That best alternative is applied one expedient
Strategy option
Distributed versus centralized processing
Changing information decision from centralized processing's data goes to decentralized end user responsibility center
Integrated versus dispersed is database
System designer shall regard data any kind ingoing in base's data and one turns in at File
Surround Strategy of System Development
Environmentally surrounding strategy is of important in term confiscation because information system of other firm may in contrast to corporate currently.
Tactics option
Done before operational scheme option
Operational scheme option
Scheme option can be agglomerated into
* Input
* Online Off-line Vs Entry Data
* keyed Vs Machine Readable is Entry Data
* Centralized Vs Decentralized is Entry Data
* Processing
* Vs's batch Realtime record update
* sequential Vs direct Access to records
* Single Vs Multiple User is of records's update
* Output
* Traditional Vs Turn Around Documents
* Structured Vs Inquiry based reports
SELECTING THE PROPER SYSTEM
Tactics compares: System than bases cost and gain relatively; There is 3 A's system trick is said more superior with another system if:
* A have inferior cost of B and gain both with
* A have inferior cost of B and A result more gain A lot of of B
* A and b have cost with but resulting gain A more A lot of.
Severally Methodics Komparasi System
* Break Even point Analyisis
* Payback Period
* Discounted PayBack period
* Internal of Return's Rate
Katagori is Cost
* Hardware
* Software
* People
* Suppliers
* Teleccommunications
* Physical sites
Cost detail
Comparing information system cost via system life, projection's analyst gets what change cost for the future and there is 3 information system cost models which is Linear, Exponential and Step Function.
Information system cost can happen really just and gets too happening chronically.
* Happening information system cost once just which is onetime cost and development cost what do happen while system development.
* Happening information system cost continually among those is reccuring cost and operational cost where this cost happens while operating information system everyday.
INFORMATION SYSTEM FACTOR
Kualitatif's factor that aim good information system performance among those
* Reducing fault zoom
* Reducing time to fix fault
* Reducing response time from workstation alternative
* Hastening penyediaan's time information
* Increasing system security
* Increasing record's source update active
* Increasing wearing satisfaction
Corporate strategy factor
* Consumer satisfaction
* Sell zoom increases
* Consumer commitment and vendor
* Product marketing information
PRESENTATION IS SYSTEM LEARNING
Doing presentation in few words
Reducing alae tech explanation detail
Presentation is clear with visual's assistive tool
If utilizes model to utilize assistive tool e.g. laptop so more informative
Emphasize gain of information system proposal with severally alternative whatever available appropriate condition which experienced by firm.
DECISION DRAWNS OUT OR NOT
If firm decides to develop system therefore information department will do succeeding process which is System Design Process.
If contrariwise therefore System Development Life Cycle (SDLC) will be discontinued.
Oft will find problem with studi's system and and usually top management will ask for to do its reworking to studi's system.
Model will word some part step which at reand sometimes information department will make mengulang's decision step before word studi's system.
With alternative, decision for mengulang one SDLC'S step in advance or not been called Go – No. –Go Decision.
Sabtu, 28 Maret 2009
Minggu, 08 Maret 2009
Observation General Development System
Developing information system get mean arrange a certain system new for replace old system in a totality or repair system be already. old system be needed change because something, that is:
1. There are the problems at old system, that problem can be in the form of:
a. Problem
Problem in old of system caused old of system can't be operate hope for to do conform.
b. Development of Organization
Development of organization caused that have arrange system at new system. Development of
organization between are necessity information more wide, volume manufacture more data
went up.
2. Reach for Opportunities
Technology information already development and quick. hardware, software and technology
communication already very fast to development.
3. There are the directives
Compiling of system new can also happen cause be directives of above management or from
outside organization like example of arrange administration.
The purpose or goal of developing a information system
Caused by troubleshoot likes on, so system development is wanted to break existing troubleshoots,
reaches to chances existing and fulfill instruction that given, supposed enhanced in bew system
development, that is:
a. Performance
upgrading about performance system new until become more effective. Performance can incense
of throughput and response time.
b. Information
upgrading about information quality that presented.
c . Economy
upgrading about benefits or profits or decreasing cost that.
d. Control
upgrading about restraint to detect and repair errors with deceits that.
e. Efficiency
upgrading about efficiency operation.
f. Services
upgrading about service the give system.
Principles of development an information system, follow as:
Development system for management after the system finish of developing.
Development system is investment financial capital the big every investment financial capital
have two consider, that is:
a. all alternative be have investigation
b. investment the best have to valuable.
c. development system of require people educated
d. stage work and duties that must be done in course of system developmeny
e. system development process must not massage
f. don't be afraid canceled project
g. documentation have to compass in development system
Waterfall Model
The waterfall model is a sequential one, consisting of the following process areas:
The requirements phase, in which the requirements for the software are gathered and analyzed, to produce a complete and unambiguous specification of what the software is required to do.
The architectural design (analysis) phase, where a software architecture for the implementation of the requirements is designed and specified, identifying the components within the software and the relationships between the components.
- The design phase, where the detailed implementation of each component is specified.
- The code and unit test phase, in which each component of the software is coded and tested to verify that it faithfully implements the detailed design.
The system integration and system test phase, in which the software is integrated to the overall product and tested.
The acceptance testing phase, where tests are applied and witnessed to validate that the software faithfully implements the specified requirements.
Model Spiral
The next step in the spiral life cycle model is to evaluate these different alternatives based on the
objectives and constraints. This will also involve identifying uncertainties and risks involved. The
next step is to develop strategies that resolve the uncertainties and risks. This step may involve
activities such as benchmarking, simulation and prototyping. Next, the software is developed by
keeping in mind the risks. Finally the next stage is planned.
The next step is determined by remaining risks. For example, its performance or user-interface risks
are considered more important than the program development risks. The next step may be
evolutionary development that involves developing a more detailed prototype for resolving the
risks. On the other hand, if the program development risks dominate and previous prototypes have
resolved all the user-interface and performance risks; the next step will follow the basic waterfall
approach.
The risk driven nature of the spiral model allows it to accommodate any mixture of specification-oriented, prototype-oriented, simulation-oriented or some other approach. An important feature of the model is that each cycle of the spiral is completed by a review, which covers all the products developed during that cycle, including plans for the next cycle. The spiral model works for developed as well as enhancement projects. In round one, a concept of operation is developed. The objectives are stated more precisely and quantitatively and the cost and other constraints are defined precisely. The risks here are typically whether or not the goals can be met within the constraints.
The plan for the next phase will be developed which will involve defining separate activities for the project. In round two the top-level requirements are developed. In succeeding the rounds, the actual development may be done. This is a relatively new model and can encompass different development strategies. In addition to the development activities, it incorporates some of management and planning activities into the model. For high-risk projects this might be a preferred model.
Iterative model
The four basic process areas of the iterative model are:
The requirements phase, in which the requirements for the software are gathered and
analyzed. Iteration should eventually result in a requirements phase that produces a complete and final specification of requirements.
A design phase, in which software architecture and components to meet the requirements are designed; this may be a new design, or an extension of an earlier design.
- An Implementation phase, when the software is coded, integrated and tested.
- A review phase, in which the software is evaluated, the current requirements are reviewed, and change and additions to requirements proposed.
The design phase develops the architecture that forms the foundation for the system and is critical to the success of the subsequent iterations. For obvious reasons, the design must facilitate change, and be robust enough to support unforeseen, future implementations. For each cycle of the model, a decision has to be made as to whether the software produced by the cycle will be discarded, or kept as a starting point for the next cycle.
This approach has been referred to as incremental prototyping. However, the temptation to create a quick prototype that cannot scale-up must be resisted--typically, this is not prototyping, although it could be. The cycle is complete when the requirements have been satisfied, and the release to the customer is made.
On some iterations--particularly early ones, a decision may have to be made to abandon the approach and begin a new.
Approaches of developing a system:
a. Classical approach versus structured approach (look at use methodology)
b. Piecemael approach versus system approach (look at target will touch)
c. Buttom-up approach versus modular approach (look at way determine necessity of system)
d. Total system approach versus modular system (look at expand way)
e. Great loop approach versus evolutionary approach (look at technology use)
Methodology is methods unitary, procedures, job concepts, rules and postulates that used by a science, art or discipline the other. Method is a manner, systematic technique to does a certain. System development methodology means methods, procedures, job concepts, rules and postulates that be used to will develop information system. Algorithm is sequence procedure to break a problem.
Three classifications of development methodology:
Functional decomposition methodologies.
Included in group this methodology is:
a. HIPO (hierarchy plus input-process-output)
b. Stepwise Refinement (sr) or Iterative Stepwise Refinement (ISR)
c. Information-Hiding
2. Data structure oriented methodologies
methodology can group return in two class, that is:
a. Data flow oriented methodologies
Included in group this methodology is:
1. SADT (structured analysis and design techniques)
2. Composite Design
3. Structured Systems Analys and Design (SSAD)
b. Data structure oriented methodologies
Included in group this methodology is:
1. JSD (jakson's Systems Development)
2. W/O (Warnier/Orr)
c. Prescriptive methodologies
Included in group this methodology is:
1. ISDOS(Information System Design and Optimization System)
2. PLEXSYS
3. PRIDE
4. SDM/70(System Development Methodology/70)
5. SPECTRUM
6. SRES(Software Requirement Engineering System) and SREM(Software Requirement Engineering Methodology)
7. Chapin's Approach
8 .DBO(Design by Objective)
9. PAD
10. HOS
11. MSR
12. PDL
Mention tools for developing a system
The Specific Characteristic Grafical Tools for Developing Systems
a.HIPO Diagram
b.Data Flow Diagram
c.Structured Chart
d.SADT Diagram
e.Warnier/Orr Diagram
f.Jakson's Diagram
The General Characteristic Grafical Tools for Developing Systems
1. Activity Charting
a. Systems Flowchart
b. Program Logic Flowchart
c. Detailed Computer Program Flowchart
d. Paperwork Flochart/Form Flowchart
e. Database Relation Flowchart
f. Process Flowchart
g. Gantt Chart
2. Layout Charting
a. Working Distribution Chart
b. Organization Chart
NonGrafical Tools for Developing Systems :
a. Data Dictionary
b. Structured English
c. Pseudocode
Analysis system is one who analyze system to study and identify that problems and determine user needs system. Programmer is one who write program code to a certain application based on has planned to get up that made 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.
1. There are the problems at old system, that problem can be in the form of:
a. Problem
Problem in old of system caused old of system can't be operate hope for to do conform.
b. Development of Organization
Development of organization caused that have arrange system at new system. Development of
organization between are necessity information more wide, volume manufacture more data
went up.
2. Reach for Opportunities
Technology information already development and quick. hardware, software and technology
communication already very fast to development.
3. There are the directives
Compiling of system new can also happen cause be directives of above management or from
outside organization like example of arrange administration.
The purpose or goal of developing a information system
Caused by troubleshoot likes on, so system development is wanted to break existing troubleshoots,
reaches to chances existing and fulfill instruction that given, supposed enhanced in bew system
development, that is:
a. Performance
upgrading about performance system new until become more effective. Performance can incense
of throughput and response time.
b. Information
upgrading about information quality that presented.
c . Economy
upgrading about benefits or profits or decreasing cost that.
d. Control
upgrading about restraint to detect and repair errors with deceits that.
e. Efficiency
upgrading about efficiency operation.
f. Services
upgrading about service the give system.
Principles of development an information system, follow as:
Development system for management after the system finish of developing.
Development system is investment financial capital the big every investment financial capital
have two consider, that is:
a. all alternative be have investigation
b. investment the best have to valuable.
c. development system of require people educated
d. stage work and duties that must be done in course of system developmeny
e. system development process must not massage
f. don't be afraid canceled project
g. documentation have to compass in development system
Waterfall Model
The waterfall model is a sequential one, consisting of the following process areas:
The requirements phase, in which the requirements for the software are gathered and analyzed, to produce a complete and unambiguous specification of what the software is required to do.
The architectural design (analysis) phase, where a software architecture for the implementation of the requirements is designed and specified, identifying the components within the software and the relationships between the components.
- The design phase, where the detailed implementation of each component is specified.
- The code and unit test phase, in which each component of the software is coded and tested to verify that it faithfully implements the detailed design.
The system integration and system test phase, in which the software is integrated to the overall product and tested.
The acceptance testing phase, where tests are applied and witnessed to validate that the software faithfully implements the specified requirements.
Model Spiral
The next step in the spiral life cycle model is to evaluate these different alternatives based on the
objectives and constraints. This will also involve identifying uncertainties and risks involved. The
next step is to develop strategies that resolve the uncertainties and risks. This step may involve
activities such as benchmarking, simulation and prototyping. Next, the software is developed by
keeping in mind the risks. Finally the next stage is planned.
The next step is determined by remaining risks. For example, its performance or user-interface risks
are considered more important than the program development risks. The next step may be
evolutionary development that involves developing a more detailed prototype for resolving the
risks. On the other hand, if the program development risks dominate and previous prototypes have
resolved all the user-interface and performance risks; the next step will follow the basic waterfall
approach.
The risk driven nature of the spiral model allows it to accommodate any mixture of specification-oriented, prototype-oriented, simulation-oriented or some other approach. An important feature of the model is that each cycle of the spiral is completed by a review, which covers all the products developed during that cycle, including plans for the next cycle. The spiral model works for developed as well as enhancement projects. In round one, a concept of operation is developed. The objectives are stated more precisely and quantitatively and the cost and other constraints are defined precisely. The risks here are typically whether or not the goals can be met within the constraints.
The plan for the next phase will be developed which will involve defining separate activities for the project. In round two the top-level requirements are developed. In succeeding the rounds, the actual development may be done. This is a relatively new model and can encompass different development strategies. In addition to the development activities, it incorporates some of management and planning activities into the model. For high-risk projects this might be a preferred model.
Iterative model
The four basic process areas of the iterative model are:
The requirements phase, in which the requirements for the software are gathered and
analyzed. Iteration should eventually result in a requirements phase that produces a complete and final specification of requirements.
A design phase, in which software architecture and components to meet the requirements are designed; this may be a new design, or an extension of an earlier design.
- An Implementation phase, when the software is coded, integrated and tested.
- A review phase, in which the software is evaluated, the current requirements are reviewed, and change and additions to requirements proposed.
The design phase develops the architecture that forms the foundation for the system and is critical to the success of the subsequent iterations. For obvious reasons, the design must facilitate change, and be robust enough to support unforeseen, future implementations. For each cycle of the model, a decision has to be made as to whether the software produced by the cycle will be discarded, or kept as a starting point for the next cycle.
This approach has been referred to as incremental prototyping. However, the temptation to create a quick prototype that cannot scale-up must be resisted--typically, this is not prototyping, although it could be. The cycle is complete when the requirements have been satisfied, and the release to the customer is made.
On some iterations--particularly early ones, a decision may have to be made to abandon the approach and begin a new.
Approaches of developing a system:
a. Classical approach versus structured approach (look at use methodology)
b. Piecemael approach versus system approach (look at target will touch)
c. Buttom-up approach versus modular approach (look at way determine necessity of system)
d. Total system approach versus modular system (look at expand way)
e. Great loop approach versus evolutionary approach (look at technology use)
Methodology is methods unitary, procedures, job concepts, rules and postulates that used by a science, art or discipline the other. Method is a manner, systematic technique to does a certain. System development methodology means methods, procedures, job concepts, rules and postulates that be used to will develop information system. Algorithm is sequence procedure to break a problem.
Three classifications of development methodology:
Functional decomposition methodologies.
Included in group this methodology is:
a. HIPO (hierarchy plus input-process-output)
b. Stepwise Refinement (sr) or Iterative Stepwise Refinement (ISR)
c. Information-Hiding
2. Data structure oriented methodologies
methodology can group return in two class, that is:
a. Data flow oriented methodologies
Included in group this methodology is:
1. SADT (structured analysis and design techniques)
2. Composite Design
3. Structured Systems Analys and Design (SSAD)
b. Data structure oriented methodologies
Included in group this methodology is:
1. JSD (jakson's Systems Development)
2. W/O (Warnier/Orr)
c. Prescriptive methodologies
Included in group this methodology is:
1. ISDOS(Information System Design and Optimization System)
2. PLEXSYS
3. PRIDE
4. SDM/70(System Development Methodology/70)
5. SPECTRUM
6. SRES(Software Requirement Engineering System) and SREM(Software Requirement Engineering Methodology)
7. Chapin's Approach
8 .DBO(Design by Objective)
9. PAD
10. HOS
11. MSR
12. PDL
Mention tools for developing a system
The Specific Characteristic Grafical Tools for Developing Systems
a.HIPO Diagram
b.Data Flow Diagram
c.Structured Chart
d.SADT Diagram
e.Warnier/Orr Diagram
f.Jakson's Diagram
The General Characteristic Grafical Tools for Developing Systems
1. Activity Charting
a. Systems Flowchart
b. Program Logic Flowchart
c. Detailed Computer Program Flowchart
d. Paperwork Flochart/Form Flowchart
e. Database Relation Flowchart
f. Process Flowchart
g. Gantt Chart
2. Layout Charting
a. Working Distribution Chart
b. Organization Chart
NonGrafical Tools for Developing Systems :
a. Data Dictionary
b. Structured English
c. Pseudocode
Analysis system is one who analyze system to study and identify that problems and determine user needs system. Programmer is one who write program code to a certain application based on has planned to get up that made 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.
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