INVESTIGATION SYSTEM CONCEPT
System investigation here is done when there is or there is a gap in the difference (gap) between the purpose of the system and actual system conditions. There are some point about Investigation System Concept :
1. Discrepancy between the objective of system and the real condition of system
2. Problem detection report is not real, because:
- the objective is too ideal
- lack of attitude and resources
- system measuring is not accurate
- the objective of system which have to be left behind
- difference between the idle system and the temporary system
3. The Problem solving
- Decompose the system is running. - Where is the investigation carried out here in detail - Getting a consensus that the ideal system - Developed several alternative - Selecting the best alternative
4. The objective of investigation have to show the problem which in fact is happened
PROBLEMS IN INVESTIGATION SYSTEM
There are some problems when conduct the investigation:
- Time
- Cost
- Science
- Politics
- Intervention
RECOMMENDATION Result of investigation is one recommendation, one that one of it is as follows:
- Don't take action whatever since undiscovered problem.
- Doing preserve system for problem what do little.
- Increasing ability or user skill at deep going or utilizes information system.
- Regarding for system modification totally.
- Placing happening problem into systems developmental plan which sh
INVESTIGATION TACTICS
We need tactics because :
- to find all issues
- Knowing the causes of the emergence of problems
- to determine the appropriate solution
Some of the tactics that can be done:
- Listen to opinions the subject of system
- Do not give the early breakthrough
- Compare the stories from the subject of system concerning in the same case
- Note the logical inconsistency problem
INVESTIGATION TECHNIQUE
Direct:
- The questionnaire
- FAQ
- Observations
Indirectly:
- Flow of procedure
- Reviewing documents
- Sample
- Tabular
SYSTEM DESCRIPTIONS At the moment found several descriptions about system, that is:
- Input
- Output
- File
- Data elements
- Transaction volume and document action
- Data Flow Diagram (DFD)
ANALYSIS REQUIREMENT
Stage of intensive interaction between the systems analyst with the end user where the system development team show their expertise to get feedback and trust so that the user get a good participation.
Four Purpose That Want Achieved:
- Explain the complete system
- Information system that describes the ideal
- Bringing information system to the ideal conditions at this time with attention to the constraints of resources
- Provide encouragement to the confidence in the system development
Method:
- FAQ
- Kuisioner
- Observation
- Analysis procedure
- Document observation
Resources problems:
- Time
- Money
- Expertise
- Technology
- External Factors
Analysis Document Requirement
- Landing analysis: Relationships with end users, the observation process, problems in data collection.
- The user needs: The need actual, reporting requirements, training needs and the influence of the new system.
- System constraints: Explain the constraints of time and cost, expertise, technology, and external factors.
- Documents such as data collection instruments, statistical consensus, the logical flow of data and physical, data elements in the initial data dictionary.
GENERATING SYSTEM ALTERNATIVES
There are several ways to approach the condition of the system at this time with the condition of the ideal system :
- Creating an alternative to solve the problem of information system.
- Alternative is best applied wisely.
Options strategies
- Distributed versus centralized processing.
Changes in decision-making information from the centralized data processing to the end user Decentralized responsibility center . Integrated versus dispersed database.
System designer must consider the data are entered in the database and enter the File
- Surround Strategy of System Development.
Designing Operational Options
The design options can be grouped into:
a. Input
- Online Vs Off Line Data Entry
- Keyed Vs Machine Readable Data Entry
- Centralized Vs Decentralized Data Entry
b. Processing
- Batch Vs Realtime record update
- Sequential Vs Direct Access to records
- Single Vs Multiple Users update of records
c. Output
- Traditional Vs Turn Around Documents
- Structured Vs Inquiry-based reports
SELECTING THE PROPER SYSTEM Compare tactics: systems based on the comparison of costs and benefits relative. There are 3 ways a system said the system is superior to the other if:
- A cost is lower than B and both are the same benefits
- A cost is lower than B and A yield advantage of more than B
- A and B have the same but the cost advantage generated a lot more.
Some Methods Comparison System,that is:
- Break Even point Analysis
- Payback Period
- Discounted payback period
- Internal Rate of Return
Cost Categories
- Hardware
- Software
- People
- Suppliers
- Telecommunications
- Physical sites
Cost Details Comparing the cost of information systems through the life of the system, analysts projected how the cost changes for the future and there are 3 models cost information system, namely Linear, and exponentially Step Function
Cost of information system can occur only once and can also occur continously.
- The cost of information systems that occur only once is ontime cost and development cost that occur during the development of the system.
The cost of information systems that occur on a continual basis are reccuring cost and operational cost where the cost of this is happened when the information system operates every day.
FACTORS INTO INFORMATION SYSTEM Qualitative factors that lead the performance information system that both of them
- Reduce errors
- Reduce the time to fix errors
- Reducing the response time from the workstation alternative
- Accelerating the provision of information
- Increase the security system
- Have active update source record
- Increase user satisfaction
CORPORATE STRATEGY FACTORS
- Customer satisfaction
- Level sales increased
- Commitment of consumers and vendors
- Information of marketing products
PRESENTING LEARNING OF SYSTEM
- Conduct a brief presentation
- Reduce technical explanation in detail
- Presenting clearly with visual aids
- If using a model using a tool such as a laptop so that more informative
- Emphasize the benefits of the proposed information system with some alternative that is appropriate conditions experienced by the company.
CONTINUING DESICION OR NOT
- If the company decided to develop the information system, the department will do next, namely the System Design Process.
- If then the System Development Life Cycle (SDLC) will be terminated.
- Often the problem will be found with the system and the study and top management will usually ask for the re-employment system to study.
- Model will describe some of the stages of the repeated and sometimes the information will make a decision before the repeat stage system of study.
- With the alternative, the decision to repeat a previous stage SDLC or not called Go - No-Go Decision.
REFFERENCE:
1. Slide Pengamatan Awal, Kebutuhan Analisis; Ngurah Agus Sanjaya ER, S.KOM, M.KOM
3/08/2009
Information System Analysis and Design Part 2
A. The Importance of Systems Development
System development can mean to compile a new system to replace a whole old ones system or to improve or to repair the system. Mentioned matter can be caused of several things:
1. There are problems in old systems
First we can see in old systems don’t operate is matching with the one which expected and two mistake which do not be intended which also can cause the truth of data become less guaranteed.
2. To reach Opportunities
In a state of market compete, efficiency of information very determining success or failure of plans and strategy which have been made arrangements for to reach for existing opportunity. Because that information can support in course of decision making to conducted by upstairs management.
3. Existence of Instruction
Compilation of new system earn also happened caused of instruction upstairs management level or from outside organization.
B. Purpose of Systems Development
We can meet the purpose or goal of developing information system such as: - to solving some problems - reach for opportunity - fulfilling given instruction
C. The organization's expectations after implementing an information system
After developing new system, expected improvement in new system. This improvement relate to PIECES, that is:
• Performance, the improvement of performance in a new system make the system will be effective. Performance can be measured from throughput and response time. Throughput is the amount of work which can be done certain in a moment and and response time is time mean which delay between two transactions.
• Information, improvement of quality of presented information.
• Economic, the improvement of benefits and advantages or decreasing cost that happened.
Control, improvement of controlling for detecting and repairing some mistake and also insincerity.
• Efficiency, improvement of operating efficiency and use resources to operate of systems with extravagance of minimum.
• Service, improvement of service given by system.
D. The principles of developing an information system
1. System for management
System must to earn to support requirement needed by management.
2. System is big capital investment
Developed systems need capital which by dozens, more than anything else if using recent technology. Hence each capital invesment have to consider two matter following :
a. Investigation of all alternative ( minimizing missing cost opportunity) Require to be done the investigation from existing alternative, where will invesment, how many advantage if chose that alternative compared to other alternative so that the alternative become most beneficial or best alternative.
b. Best invesment have to assess.
Good investment has to be valuable. The best chosen investment of course not represent most beneficial. Investment told to profit if its benefit or result of returning is bigger than expense to obtaining it.
3. System need educated people
Educated non meaning a student, but can also with on-the-job-training to use system.
4. Step work and jobs for process of systems development
Before process of system development doing, hence must to be made beforehand schedule work to determine job steps. System Development Life Cycle generally show steps work and job duties which must be do.
5. Process of systems development don’t must to step by step.
This principle seen to be oppose against number principle four, but do not that way. Step work can just doing together, that is when ones step job done also can do other step work hence execution of step work become at a time. This matter is done to be process is continue without one step work is finish. ”Remember time is money “.
6. Don’t fear to canceled projects.
Hence the system development process better be canceled because later will permeate fund which is more with result of which no advantage. This will fritter cost.
7. There must be documentation
Documentation of system development there must be. This documentation is made not after system finish but when processing or developing system do. So that this documentation can be used as tools communications between system analyst with user.
E. Systems Development Life Cycle
1. WaterfallModel
The image below is the classic Waterfall model methodology, which is the first SDLC method and it describes the various phases involved in development.
Requirement
At this phase happened is gathering the requirement of system base. The examples are software, human being, and database. This phase also include, gathering of requirement at strategic business storey level and business area storey level.
Design
In 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
Design have to be translated into machine language form. The making of code step reside in this phase. If the design completely done, making the code can be finished mechanically.
Verification
After made the program code, program examination is started. Examination process focus at internal logic software, examination to find mistake and ascertain input is limited that will give result of appropriate actual.
Maintenance
Inevitably the system will need maintenance. Software will definitely undergo change once it is delivered to the customer. There are many reasons for the change. 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 that picture we can see about 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-users; 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 steps in the spiral model can be generalized as follows:
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. Than A preliminary design is created for the new system. Second 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.After that 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. the customer's option, the entire project can be aborted if the risk is deemed too great. 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. And 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. Besides at this phase, the customer / client have to be trained by the way of using it.
F. Approach of System Development There are several approaches to developing a system, that is:
1. Classical approach is an approach of developing a system that follow steps at system life cycle without supplied with tools and techniques.
2. 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.
Piecemeal approach vs. system approach Piecemeal approach will only emphasize at an just application or activity. This approach will only attention target of that just application or activity without seeing target of is overall of organization. Total-system approach is the approach which developing a system together according to comprehensive. This approach less synchronized for complex system, because will be difficult be developed. This approach is 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 is feature structured approaches.
G. The meaning of methodology, method and algorithm
We know there are approaches in developing a system. Now how to do these approaches? To developing a system, it is required by methodologies. Methodology are utilized methods, procedures, professions concept, rules and postulates that used by a science, art or the other. Method is a way of systematic technique to do something. And algorithm is medley procedural to solve problems.
H. The classifications of development methodology
Three classifications of development methodology:
• A. Functional decomposition methodologies Functional decomposition is emphasizing to divide a system becomes subsystem. There are the include in this group methodologies such as:
1. HIPO
2. Stepwise refinement
3. Information hiding.
• B. Data-oriented methodologies Data-oriented is emphasizing on processed data characteristic. This approach can be grouped in two:
a. Data-flow oriented: based on dividing system to modules pursuant to elements data types and logic behavior of these modules in system. There are the include in this group methodologies such as SADT (Structured Analysis and Design Techniques), Composite Design.
b. Data structure oriented: emphasizing structure of input and output in system. There are the include in this group methodologies such as JAD (Jackson's system development), W/O (Warnier/Orr).
• C. Prescriptive methodology
This methodology usually has been provided by software maker factory. In this methodology including:
o - ISDOS (Information System Design and Optimization System)
o - PLEXSYS
o - PRIDE
o - SDM/70
o - SPECTRUM
o - SRES and SREM, etc.
I. Tool for Developing System
Tools which is used in an methodologies generally in the form of diagram or picture or graph. Besides in form of picture, tools used also there is which in the form of graph or picture like for example data dictionary, structured english, pseudocode, and also forms to note and present data. The tools there are in the form of diagram and chart, example:
1. HIPO diagram
2. Data Flow diagram
3. Structured chart
4. SADT diagram
5. Warnier/Orr diagram
6. Jakson’s diagram
Besides the tools that mention above, there are utilizes that used at all of methodology. The tools as a chart set that grouped by:
• a. Activity charting: to figuring activity, example: chart's substituting, flowchart, etc.
• b. Layout charting: to figuring layout
• c. Personal relationship charting: to figuring person relationship, example: organization chart, working distribution chart
J. Techniques used in developing a system
Techniques used in developing a system, as follows:
• a. Project management techniques, example: CPM and PERT. This techniques used to scheduling project,
• b. Fact finding techniques, techniques to gather and determines data / fact. The techniques that is:
o – Interview, Interview give opportunity to interviewer to motivate customer to answer freely.
o – Observation, Collected data very accurate.
o – Questionnaires, Can bother observation object
o – Sampling, Questionnaire good to resource which is many and spread over.
• c. Cost effectiveness analysis or cost-benefit analysis
• d. Techniques to run meeting
• e. Inspection techniques/walkthrough
K. The differences of being a system analyst and a programmer
A title is just a title and what the people do under those titles can differ from company to company, but in general, a computer programmer translates a design into an actual computer program. A computer analyst, or more commonly called a systems analyst or business analyst or software architect will analyze a company process and design a software package that will improve that process. The systems analysts are usually individuals that bridge the gap between the real world and the programming world. They can speak "both languages" by helping the computer programmers understand the business process and by helping the software users understand the computer programming process. The two titles are similar to the difference between a home builder and an architect.
References:
Hartono, Jogiyanto.2005.Analisis dan Desain Sistem Informasi: Pendekatan Terstruktur, Teori dan Praktik Aplikasi Bisnis. Yogyakarta: Andi.
http://wiki.answers.com/Q/Difference_between_computer_programmer_and_computer_analyst
System development can mean to compile a new system to replace a whole old ones system or to improve or to repair the system. Mentioned matter can be caused of several things:
1. There are problems in old systems
First we can see in old systems don’t operate is matching with the one which expected and two mistake which do not be intended which also can cause the truth of data become less guaranteed.
2. To reach Opportunities
In a state of market compete, efficiency of information very determining success or failure of plans and strategy which have been made arrangements for to reach for existing opportunity. Because that information can support in course of decision making to conducted by upstairs management.
3. Existence of Instruction
Compilation of new system earn also happened caused of instruction upstairs management level or from outside organization.
B. Purpose of Systems Development
We can meet the purpose or goal of developing information system such as: - to solving some problems - reach for opportunity - fulfilling given instruction
C. The organization's expectations after implementing an information system
After developing new system, expected improvement in new system. This improvement relate to PIECES, that is:
• Performance, the improvement of performance in a new system make the system will be effective. Performance can be measured from throughput and response time. Throughput is the amount of work which can be done certain in a moment and and response time is time mean which delay between two transactions.
• Information, improvement of quality of presented information.
• Economic, the improvement of benefits and advantages or decreasing cost that happened.
Control, improvement of controlling for detecting and repairing some mistake and also insincerity.
• Efficiency, improvement of operating efficiency and use resources to operate of systems with extravagance of minimum.
• Service, improvement of service given by system.
D. The principles of developing an information system
1. System for management
System must to earn to support requirement needed by management.
2. System is big capital investment
Developed systems need capital which by dozens, more than anything else if using recent technology. Hence each capital invesment have to consider two matter following :
a. Investigation of all alternative ( minimizing missing cost opportunity) Require to be done the investigation from existing alternative, where will invesment, how many advantage if chose that alternative compared to other alternative so that the alternative become most beneficial or best alternative.
b. Best invesment have to assess.
Good investment has to be valuable. The best chosen investment of course not represent most beneficial. Investment told to profit if its benefit or result of returning is bigger than expense to obtaining it.
3. System need educated people
Educated non meaning a student, but can also with on-the-job-training to use system.
4. Step work and jobs for process of systems development
Before process of system development doing, hence must to be made beforehand schedule work to determine job steps. System Development Life Cycle generally show steps work and job duties which must be do.
5. Process of systems development don’t must to step by step.
This principle seen to be oppose against number principle four, but do not that way. Step work can just doing together, that is when ones step job done also can do other step work hence execution of step work become at a time. This matter is done to be process is continue without one step work is finish. ”Remember time is money “.
6. Don’t fear to canceled projects.
Hence the system development process better be canceled because later will permeate fund which is more with result of which no advantage. This will fritter cost.
7. There must be documentation
Documentation of system development there must be. This documentation is made not after system finish but when processing or developing system do. So that this documentation can be used as tools communications between system analyst with user.
E. Systems Development Life Cycle
1. WaterfallModel
The image below is the classic Waterfall model methodology, which is the first SDLC method and it describes the various phases involved in development.
Requirement
At this phase happened is gathering the requirement of system base. The examples are software, human being, and database. This phase also include, gathering of requirement at strategic business storey level and business area storey level.
Design
In 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
Design have to be translated into machine language form. The making of code step reside in this phase. If the design completely done, making the code can be finished mechanically.
Verification
After made the program code, program examination is started. Examination process focus at internal logic software, examination to find mistake and ascertain input is limited that will give result of appropriate actual.
Maintenance
Inevitably the system will need maintenance. Software will definitely undergo change once it is delivered to the customer. There are many reasons for the change. 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 that picture we can see about 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-users; 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 steps in the spiral model can be generalized as follows:
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. Than A preliminary design is created for the new system. Second 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.After that 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. the customer's option, the entire project can be aborted if the risk is deemed too great. 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. And 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. Besides at this phase, the customer / client have to be trained by the way of using it.
F. Approach of System Development There are several approaches to developing a system, that is:
1. Classical approach is an approach of developing a system that follow steps at system life cycle without supplied with tools and techniques.
2. 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.
Piecemeal approach vs. system approach Piecemeal approach will only emphasize at an just application or activity. This approach will only attention target of that just application or activity without seeing target of is overall of organization. Total-system approach is the approach which developing a system together according to comprehensive. This approach less synchronized for complex system, because will be difficult be developed. This approach is 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 is feature structured approaches.
G. The meaning of methodology, method and algorithm
We know there are approaches in developing a system. Now how to do these approaches? To developing a system, it is required by methodologies. Methodology are utilized methods, procedures, professions concept, rules and postulates that used by a science, art or the other. Method is a way of systematic technique to do something. And algorithm is medley procedural to solve problems.
H. The classifications of development methodology
Three classifications of development methodology:
• A. Functional decomposition methodologies Functional decomposition is emphasizing to divide a system becomes subsystem. There are the include in this group methodologies such as:
1. HIPO
2. Stepwise refinement
3. Information hiding.
• B. Data-oriented methodologies Data-oriented is emphasizing on processed data characteristic. This approach can be grouped in two:
a. Data-flow oriented: based on dividing system to modules pursuant to elements data types and logic behavior of these modules in system. There are the include in this group methodologies such as SADT (Structured Analysis and Design Techniques), Composite Design.
b. Data structure oriented: emphasizing structure of input and output in system. There are the include in this group methodologies such as JAD (Jackson's system development), W/O (Warnier/Orr).
• C. Prescriptive methodology
This methodology usually has been provided by software maker factory. In this methodology including:
o - ISDOS (Information System Design and Optimization System)
o - PLEXSYS
o - PRIDE
o - SDM/70
o - SPECTRUM
o - SRES and SREM, etc.
I. Tool for Developing System
Tools which is used in an methodologies generally in the form of diagram or picture or graph. Besides in form of picture, tools used also there is which in the form of graph or picture like for example data dictionary, structured english, pseudocode, and also forms to note and present data. The tools there are in the form of diagram and chart, example:
1. HIPO diagram
2. Data Flow diagram
3. Structured chart
4. SADT diagram
5. Warnier/Orr diagram
6. Jakson’s diagram
Besides the tools that mention above, there are utilizes that used at all of methodology. The tools as a chart set that grouped by:
• a. Activity charting: to figuring activity, example: chart's substituting, flowchart, etc.
• b. Layout charting: to figuring layout
• c. Personal relationship charting: to figuring person relationship, example: organization chart, working distribution chart
J. Techniques used in developing a system
Techniques used in developing a system, as follows:
• a. Project management techniques, example: CPM and PERT. This techniques used to scheduling project,
• b. Fact finding techniques, techniques to gather and determines data / fact. The techniques that is:
o – Interview, Interview give opportunity to interviewer to motivate customer to answer freely.
o – Observation, Collected data very accurate.
o – Questionnaires, Can bother observation object
o – Sampling, Questionnaire good to resource which is many and spread over.
• c. Cost effectiveness analysis or cost-benefit analysis
• d. Techniques to run meeting
• e. Inspection techniques/walkthrough
K. The differences of being a system analyst and a programmer
A title is just a title and what the people do under those titles can differ from company to company, but in general, a computer programmer translates a design into an actual computer program. A computer analyst, or more commonly called a systems analyst or business analyst or software architect will analyze a company process and design a software package that will improve that process. The systems analysts are usually individuals that bridge the gap between the real world and the programming world. They can speak "both languages" by helping the computer programmers understand the business process and by helping the software users understand the computer programming process. The two titles are similar to the difference between a home builder and an architect.
References:
Hartono, Jogiyanto.2005.Analisis dan Desain Sistem Informasi: Pendekatan Terstruktur, Teori dan Praktik Aplikasi Bisnis. Yogyakarta: Andi.
http://wiki.answers.com/Q/Difference_between_computer_programmer_and_computer_analyst
Langganan:
Postingan (Atom)