The importance of developing an information system, where in this term means developing a new system, is because the old system needs to be replaced due to the reason :
a. There’re problems that occur in the old system. In example :
1) System’s amiss.
Could be in the form of on purposed fraud or coincedental mistake that makes the inconsistency on the data.
2) Organizational growth.
The necessity to build a new system by organizational growth was because the need of information is going wide, the volume of data processing is increasing, and the changes of new accountant fundamental.
b. To achieve opportunities.
On competing trade, information rate or time efficiency determines the succesive of the strategy that had been planned to achieve the opportunities. So we need to gain advantage of this matter to make the opportunities come to our company, not to the others.
c. The existence of directives.
A new system can be born of superior level order or external organization factor. In example, a government regulation.
2. What is the purpose or goal of developing an information system?
Because of the presence of the problems, opportunities, and the directives, so a new system needs to be developed in order to solve those problems. That is to resolve the problems, to gain the opportunities, and to fill in the directives.
3. What are the organizations expectations after implementing an information system?
On implementing the new system, we expect to gain enhancement in this new system. This new enhancement related to this PIECES :
a. Performance.
Performance can be measured by throughput dan response time. Where throughput means the total amount of work that can be done on one certain time, and response time means an average of delayed time between two transactions or work plus response period to respond that work.
b. Information.
An increasing of information quality.
c. Economy.
An increasing in advantages or benefits or decreasing in cost.
d. Control.
An increasing in control to detect and fix the failure or deception that would happen.
e. Efficiency.
Efficiency here related with how the resource being used with a minimum waste. Efficiency can be measured from output divided with the input.
f. Services.
An increasing of services that was given by the system.
4. What are the principles of developing an information system?
a. The system that was developed is for a managements usage.
Because the one who will use the system is in management level, so the new system must support the requirement of the management level itself.
b. The system that was developed is a big investment asset.
In investing asset, we must consider :
1) All available alternatives must be investigate.
If all other available alternatives were to be ignored and we had invested the fund to certain project, so the investor here had lose the opportunities to invest the fund to other investment. Therefore, from some available investment alternatives, all must be investigated to specify the best alternatives or the most prosperous one.
2) The best investment here must be valuable.
This investment can be said prosperous if it is valuable, which means the benefit or the revenue is bigger than the cost to get them. Where the cost benefit analysis or cost effectiveness analysis can be used to determine whether the investment project is valuable or not.
c. The system that was developed needs educated people.
Peoples that was involved in development as well as in application of the system, must be educated about the problems that exist and educated with solution-solution that it should take. And educated here, doesn’t mean to be a formally colleger, but also can be done with on-the-job-training.
d. Working phase and assignments that have to be done in system development process.
Before doing the system development process, earlier we need to make a working schedule that shows the working phase and assignments that shall be done, so that the system development process could be done and completed succesfully due to the time given and planned budget.
e. System development process mustn’t be in sequence.
Working phase from system development process represents the actions that needs to be done and this actions mustn’t be in sequence, but could be done all together.
f. Don’t be afraid to cancel a project.
For some case where a project must be cancelled because it was not worthy to continue, so the decision must be taken clear. Hesitation to keep going on the project that was unworthy to continue because of the invested funds so far on the project, will just make another waste of the investment itself.
g. Documentation is a must to be the guidance in developing system.
Many system analysts fail to make a documentation. They usually make this documentation after the development of the system or even there’re some that don’t make it. This problem must be revised. So for other system analyst, we suggest to make the documentation all together with the ongoing process of developing system. Because this documentation can be produced from the working output in every steps on system development.
5. System development life cycle.
a. Waterfall Model
This life cycle model take the form of the waterfall, because it goes only one way, like a waterfall that goes only from the top to the bottom. This model also called a sequential model or a sequential linear model. Like what we can see from the upper picture, this model goes one way as sequence from the Requirements phase, to the Design phase, then Implementation phase, Verification phase, and Maintenance phase.
So the process only goes once, as for at the requirements phase we gather all the specification and the requirements of the system, and then we start to make a sketch of design that later will be the systems design at the Design phase, and then implementing all of the planning before like the design, the systems spec and req, and so on. Or on the other hand we executes all the planning here on the Implementation phase. And then at the Verification phase we test all the thing that we have implemented before and make sure that the system runs smoothly and have no problems. After that, we only have one last phase that is Maintenance phase. In this phase, we maintenance the system that means, if there’re any problems regarding the systems, we fix it here. And keep balancing of the process of the systems.
b. Iterative Model
At iterative model, it actually resembles the waterfall model or sequential model. The phases here don’t differ very much. It only different in iterative processes only. This model has a corrective looping phase that is useful to correct failure in the systems. In the picture, it shows on the looping phase between : Planning, Requirements, Analysis & Designs, Implementation, Testing, and Evaluation. These phases show looping condition that means if there’re failure when implementation phase, we need to tests the system again and check where’s the failure going on, and then evaluates them again to be able make a new plan of system, that has a correction of the failure before. If the system has been recreate again and pass the implementation phase, then the system can be deployed (at Deployment phase).
c. Spiral Model
This spiral model at first was proposed by Boehm. Spiral model here is an evolutionary model that joins the two characteristics of iterative model with a control process and systematic aspects from the sequential model. This spiral model splits some activity framework, that also called tasks region, into 6 tasks region. They’re :
1) Customers communication.
Tasks that was needed to develops an effective communication between developer and the customer.
2) Planning.
Tasks that was needed to defined the resources, accurate time, and other related project information.
3) Risk Analysis.
Tasks that was needed to estimate the risks, either in management or technical.
4) Engineering.
Tasks that was needed to build one or more representation of that application.
5) Construction and Deployment.
Tasks that was needed to construct, testing, installing, and giving services to the customer (i.e. training and documentation).
6) Customer Evaluation.
Tasks that was needed to get a feedback reaction from the customer based on software representation evaluation, that was made during engineering phase, and implemented during installation phase.
6. Approaches in system developments.
There’re 5 approaches here. They’re :
a. Classical approach vs Structural approach
Classical approach develops the system with following the phase in systems life cycle. This approach emphasizes system development could be successful if we follow the phase in systems life cycle. But in fact, this approach doesn’t give an advanced guidance about how to do those phase in detailed. So we need a new approach, and so called the structural approach. This approach tries to provide a system analyst with an addition tools and techniques to develops system besides it still follows the idea from system life cycle.
1) Classical Approach.
Classical approach or so called the conventional approach is an approach that follows the phase in systems life cycle without providing itself with adequate tools and techniques. So there goes the problems in this approach, they’re :
a) Developing software has become difficult.
Classical approach gives a minimal tools and techniques in developing a system, and as the consequences the development of software has become aimless and hard to be done by the programmer.
b) The upkeep cost or systems maintenance becomes expensive.
The most expensive cost of system developments is in the maintenance phase. Why the most cost is in it, because the systems documentation is not perfect and not structured. So that when maintenancing system, it has become troubles.
c) Possibility of the system’s making a mistake is high.
Classical approach doesn’t provide the system analyst the procedures to do a test to the system, so that the possibility of the systems to make mistakes is become higher.
d) The success of the systems becomes less guaranteed.
Classical approach didn’t involved the systems user in developing system, so that the needs of the systems user become less suited with what was hoped for before, and as the consequences the applied systems also becomes unsuccessful.
e) Problem in implementing systems.
Because of the less involvement of the systems user in systems development phase, so the systems user will only know the new applied systems in the implementation part only. That will later make the user becomes frustrated because of the lack to operating the system properly.
2) Structural approach.
With only following the phase in system life cycle, wouldn’t make the information system development becomes success. Therefore we need a system development approach to revised them. So there’re this structural approach. This structural approach was equipped with tools and techniques that was needed in developing system, so that we will get a system with a more good and clear structure for the final output.
b. Piecemeal approach vs System approach
Piecemeal approach is a system development approach that emphasizing on an event or certain application only. In this approach, choosen event or application was developed without paying its attention in information system or without paying attention of the global objectives from the organization, but just paying attention on objective of the event or their application only.
But in system approach, we do pay attention for the information system as one unity that was integrated one another for each event or the application. This approach also paying attention on the global objective of the organization, not only the objective of the information system.
c. Bottom-up approach vs Top-down approach
Bottom-up approach, starts from the lowest level of the organization that is on operational level where the transaction happens. This approach starts from formulation of the necessity to handle the transaction and going up to the upper level with formulating the information needs based on that transaction.
On the other hand, the top-down approach starts from the top level organization, that is on the strategic planning level. This approach starts from defining the objectives and policies of the organization. The next step is to do the information needs analysis. After the information needs being defined, so the process goes down one level to the transaction processing, that is to defined the output, input, database, operational procedures and controls.
d. Total-system approach vs Modular approach.
Total-system approach is an approach that develops the system simultaneously in the mass. Differ from the modular approach, where this approach tries to solve a complex system into some part or simple modul, so that the system will be easier to understand and develop.
e. Great loop approach vs Evolutionary approach.
Great loop approach implements a simultaneous change in the mass using advance technology. Differ from the evolutionary approach where it only implements advance technology for the application that need it at that time only and will keep developing for the next period following the necessity of the evolving technology.
7. Please explain the methodology, method, and algorithm.
Methodology is a unity of methods, procedures, working concepts, rules and postulates that was used by certain knowledges, arts or other disciplines. But the method here is a procedure or systematical technique that was used to doing something. And so the system development methodology is a methods, procedures, working concepts, rules and postulates that was used to develops an information system. So then the procedure sequences to solve this problems was known by “algorithm”.
8. Three classification of system development methodology :
a. Functional decomposition methodologies.
This methodology emphasizing in splitting from system into a more small subsystems, so that it will be easier to understand, designed and applicable. The one that includes in this methodology are :
· HIPO (Hierarchy plus Input-Process-Output)
· Stepwise refinement (SR) atau Iterative stepwise refinement (ISR)
· Information-hiding
b. Data-oriented methodologies.
This methodology emphasizing in the characteristics of the data that will be processed. This methodology can be classified into 2 class, those are :
1) Data-flow oriented methodologies.
This methodology was based on the splitting from the system into moduls that was based from the data element types and logic characteristic of that modul in the system. The one that includes in this methodology are :
· SADT (Structured Analysis and Design Techniques)
· Composite design
· Structured Systems Analysis and Design (SSAD)
2) Data-structure oriented methodologies.
This methodology emphasizing in structure from the input and output in the system, where this structure will later be used as a base structure for the systems. The one that includes in this methodology are :
· JSD (Jakson’s systems development)
· W/O (Warnier/Orr)
c. Presciptive methodologies.
The one that includes in this methodology are :
· ISDOS (Information System Design and Optimization System)
ISDOS is a software that was developed in the University of Michigan, where its function is to automated the process of information system development.
· PLEXSYS
The function of PLEXSYS is for transforming a high level language statement into an executable code for a configuration of the desired hardware. PLEXSYS is a complement for ISDOS, where ISDOS was used in determining needs, and PLEXSYS was used in producing the program code automatically.
· PRIDE
PRIDE was offered by a company in America, by M.Bryce & Associates. PRIDE is an integrated software good for designing / analizing system structure, data management, project management and documentation.
· SDM / 70
SDM (System Development Methodology / 70) was developed and sold in the market by a company in America, by Atlantic Software, Inc. SDM / 70 is a software that contains a collection of methods, estimations, documentations and administrative reference to help the user to develops and maintenancing system effectively.
· SPECTRUM
SPECTRUM is a system developmenty methodology that was developed and sold in the market by an American company named SII (Spectrum International Inc.). This software has some version for different needs, like SPECTRUM-1 (for conventional life cycle), SPECTRUM-2 (for structured project management system) and SPECTRUM-3 (for online interactive estimator).
· SRES and SREM
SRES (Software Requirement Engineering System) was developed by TRW for SDS (Software Development System) from US Airforce. In SRES, the user needs was defined in RSL (Requirement Statement Language). And the methodology that was based on this software is called SREM (Software Requirement Engineering Methodology). This software has some identic concepts with ISDOS.
· Some other prescriptive methodologies :
- Chapin’s approach
- DBO (Design By Objective)
- PAD (Program Analysis Diagram)
- HOS (Higher Order Software)
- MSR (Meta Stepwise Refinement)
- PDL (Program Design Language)
9. Tools for Developing Systems are :
- Graphical tools :
a. HIPO Diagram, used in HIPO Methodology and in other methodology.
b. Data Flow Diagram, used in Structured Systems Analysis and Design methodology.
c. Structured Chart, used in Structured Systems Analysis and Design methodology.
d. SADT Diagram, used in SADT methodology.
e. Warnier / Orr Diagram, used in Warnier / Orr methodology.
f. Jakson’s Diagram, used in Jackson System Development methodology.
- Other useful tools are charts, which can be used in almost all other methodologies. These charts are :
a. Charts for explaining activity (Activity Charting) :
1) Systems Flowchart
2) Programs Flowchart, can be in form of :
a) Program Logic Flowchart
b) Detailed Computer Program Flowchart
3) Paperwork Flowchart or Form Flowchart
4) Database Relationship Flowchart
5) Process Flowchart
6) Gantt Chart
b. Charts for explaining layout (Layout Charting)
c. Charts for explaining personal relationship (Personal Relationship Charting) :
1) Working Distribution Chart
2) Organization Chart
10. Techniques used in developing a system :
a. Project Management Technique, that is CPM (Critical Path Method) and PERT (Program Evaluation and Review Technique). These techniques was used for scheduling project.
b. Fact Finding Techniques, that is a technique to gather data and finding facts in the event to study the existing system. Some of these techniques are :
1) Interview
2) Observation
3) Questionaires
4) Sampling
c. Cost Effectiveness Analysis or Cost benefit Analysis
d. Technique for performing meeting
e. Technique for inspection / walkthrough
11. System Analyst is a person whose job is to analize the system (learn the possible problems that might occur and determine the necessity of the systems user) to identify the reasoned solution possible. The one who understand well about the business aspects of the systems are the systems user itself. So system analyst is the right people to develops information system based on the needs that user wants, while the programmer develops the program application.
The programmer on the contrary with systems user, has more understanding in computer technology, but has less understanding in business aspects and requirement that was needed by systems user. Because of that, we need system analyst to bridge the gap between programmer and systems user. Because he / she, has a great understanding for the two aspects, that is the computer technology aspects to be able to communicate with programmer, and the business aspects to understands what systems user wants.
Knowledge and skills that was needed by most analyst system :
a. Knowledge and skills about data processing technique, computer technology, and computer programming.
- Technical skill that has to be owned includes the skills in using tools and technique for developing application software and skills in using computers.
- Technical knowledge that has to be owned includes the knowledge of computer hardware, data communication technology, computer languages, operation system, utilities and other softwares.
b. Knowledge about business in general.
This knowledge must be owned because nowadays business application is the most application applied. So the knowledge about business is also needed here. This business knowledge includes finance accounting, money accounting, management accounting, management control system, production marketing, personnel management, finance, organization behaviour, company policies, and other business aspects.
c. Knowledge about quantitative method.
Quantitative method that generally needs are : linear programming, dynamic programming, regression, network, decision tree, trend, simulation, and so on.
d. Solving problems skills.
System analyst must have skills to splits complex problems into small subproblems, analyze them, and then unite them again to be a system that can solve the previous problems.
e. Communication skills inter-personnel.
System analysts must have skills to establish communication verbally or in written. These skills was needed in interview, presentation, meeting, and making documentation.
f. Skills to build relationships between personnels.
This skill was needed by system analyst because system analyst need to establish a good relationship between the personnel, in order to avoid a floppy relationships that can cause the job becomes ineffective.
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