Importance of developing an information system
Development of the system may mean preparing a new system for replace the old system or improve the overall system existing.
Importance of developing an information system:
• There is a problem (problem) that arise in the old system
The problems that arise can be:
· Irregularity
· Organizational growth
• To seize the opportunity (opportunities)
Information technology has developed so quickly
• The instructions (directives)
Goal is the development of the system:
To complete the problem (problem) that arise in the old system
The problems that arise can be:
· irregularity in the development of System Organization
In an organization there are some data that must be processed, when Organization developing processed data needed for the system the greater good, if not use the information system so that both Organization growth will be hampered
opportunity
· Growth Organization
Information systems also help in achieving opportunities. And also make it easier to capture opportunities.
Referrals Information system can more quickly provide instruction, for example, confusion is a company looking for documents, the system with the information we provide instructions directly to the system to search for it.
Expected on the new system
Has been developed with the new system, the expected increase will occur, the increase in the new system.
• Performance
Improvement of the performance of the new system which will be most effective. Performance can be measured from the throughput and response time.
• Information
Improving the quality of information presented.
• Economy
Improvement of the benefits or the benefits or a decrease in the cost-reduction.
• Control
Detect and fix errors that occur and will occur.
• Efficiency
Improvement of operational efficiency.
• Services
Improvement of the services provided by the system.
The principle of the development system
· The system is developed for management
· The system developed is a large capital investment
Investment capital should consider 2 things:
1. 1. All alternatives should be investigated
2. 2. Investment should be the best value
· System developed need educated people who
Stages of work and tasks that must be made in the system development process
· The development of the system does not have to order
· Do not be afraid to cancel the project
· Documentation must be available to guide the development of the system
Life cycle development system
1. Stages of Planning System (System Planning)
2. Stages Analysis System (System Analiysis)
3. The design phases of system (System Design)
4. Stages Selection System (System Selection)
5. System Implementation Stages (System Implementation)
6. Stages Care System (System Maintenance)
SI Model development
(Life Cycle SI)
- CLASIC life cycle / waterfall model, consists of the phases of planning system (engineering system), needs analysis, design, writing programs, testing and treatment system.
- prototyping model, starting with collection needs and improvements, the design quickly, the establishment of prototype, evaluation of customer prototype, repairing prototype and final product.
- Rapid Application Development (RAD) model, with business activity began modeling, data modeling, process modeling, generation and application
testing. - Evolutionary model that can be a model incremental or spiral model Incremental model is a combination model sequential linier with prototyping (device word processing software with different versions). While the spiral model of analysis risk. If the analysis shows there is a risk uncertainty of demand, the development system can be stopped.
- Engineering generation-to-four (4GT), starting with collection needs, design strategies, implementation and testing using a 4GL.
Waterfall Model
Contains a series of activities such as the process has been described above and presented in a separate process, such as the requirement specification, design implementation software, testing . After each step is defined, this step in the sign off and followed the development in the next step.
The steps that are important in this model is
- The analysis and specification
Services, goals and constraints resulting from consultation with users system. Then everything is made in the form that can be understood by users and staff developers.
- Design systems and software
Divide the system design process needs to be system software or hardware. The process produces an overall system architecture. Design software, including the functions of system software that may be in the form of the transformation in one or more programs that can be run.
- Implementation and unit testing
During this stage, the design software we realize as a complete program or program unit. Test units, including units that each test according to specification.
- Integration and system testing
Unit tested and integrated the program into a complete system for making sure that software requirements have been met. After testing, the system was delivered to the customer.
- Operation and maintenance
This phase is long. System installed and used. Maintenance, including correction of errors not found in the previous step. Improvements to the implementation of the system and increasing service needs of the new system as found.
Weakness Waterfall
• Iterations frequent cause a new problem
• Client trouble to declare all desires explicitly beginning stage of development.
• The s / w which will be developed known long after the project development begins
Prototype model
- provides a method with about a complete system, customers can see the modeling system from the side view and techniques procedural that will be built
- On the efficiency development Testing algorithm, the interaction with the OS and user
- Discover the top; paper model, work model, program
- evaluated by the user and used to process again needs
- The developers will learn understand the needs and user desires.
- Identify the needs of consumers, systems analyst will be to study feasibility studies and needs to users, including interface model, engineering procedural and technology that will used.
Summary prototype
- Identify the needs: analysis needs of the prospective user
- Quick design: the creation of a global design to form the s / w instance
- Build prototype: the creation of s / w prototype including testing and completion
- Evaluate customer: evaluate prototype and refine analyst needs of prospective users
- Preparation & implementation: the creation of including the actual design, coding, and testing
The weakness of the prototype
· unconsciousness user that is only a model of the early models is not the end
· Developers sometimes create implementation of the markets.
· techniques and tools that are not optimal in the prototype that will still be used on s / w indeed.
RAD Model
- Rapid Application Development
- The development of s / w in sequential linier
- adaptation do high speed, can be made in pace with the development approach component-based
- If the data, clear analysis, and the scope of small
the RAD can be used with both - Often also called a 'high speed version' of waterfall model,
- Emphasis on development cycles a short
- RAD approach to follow the following phases;
- Business modeling, the flow of information from model with the function;
information is affecting business, who appear, who is issue, the information I given, Who processing? - Data modeling; Part of the modeling business defined in a set of data objects.
- The characteristics (attributes) of each object identified and related
- The process of modeling, the object data will be implemented on the business functions.
- Descriptions for the built additional modifications, deletion, or return the data object.
- Data modeling; Part of the modeling business defined in a set of data objects.
- The characteristics (attributes) of each object identified and related
- The process of modeling, the object data will be implemented on the business functions.
- Descriptions for the built additional modifications, deletion, or return the data object.
- Application generation, Conducting re-use components that have (if possible)
- Or make use of return components if required.
- Testing / turnover, the RAD emphasizes the use of return and program components are ready to test
Weakness RAD
- Model of the (project scale), resources requires good and solid
- Requires commitment developer and the same user to be completed quickly accordance with the plan
System development approach
• A structured approach versus classical approach (seen from the methodology used)
• Piecemeal approach versus system approach (seen from the target to be achieved)
• The bottom-up approach versus top-down approach (seen from how to determine the needs of the system)
• Total-system approach versus modular approach (seen from the way the developing)
• Great loop- approach versus evolutionary approach approach (seen from the technology that will be used)
A structured approach versus classical opponent approach
Classical approach
• Stages in SDLC-stage
• Not to include users, system analysts put more emphasis
• The problem: the development of hard, expensive treatment, the possibility of error, success is less assured, the problems in the implementation of
Structured approach
• User involvement from the beginning to determine the needs of the system
• Using tools-tools such as data flow diagrams
Piecemeal approach versus system approach
Piecemeal approach
• Emphasizing on an application or event
• Don’t override the overall target
System approach
• Viewing the system as a whole is unity
• Emphasizing the achievement of overall objectives
Bottom-up approach versus top-down approach
Bottom-up approach
• Starting from the bottom level of the operational
• It is the characteristics of classical
• Known by the term data-analysis
Top-down approach
• Starting from the top-level strategy planning
• It is the characteristics of structured
• Also known to the decision-analysis
Total-system approach versus modular approach
Total-system approach
• Develop a system simultaneously and comprehensively
• It is the characteristics of classical approach
Modular approach
• break a complex system into parts of a simple
• System to be developed on time, easy to understand and kept
• It is the characteristics of structured
Great loop- approach versus evolutionary approach approach
great-loop approach approach
• Develop a system simultaneously using the advanced technology
• At risk and spend a lot of high cost
evolutionary approach approach
• Applying advanced technology for application-specific applications
• Developed for the needs
• Save the cost and can follow the development of technology
System Development Methodology and algorithm
Methodology is: Unity methods, procedures, concepts of employment, rules and postulate used by science knowledge, art or other disciplines.
Method is: One way / technique to do something systematic. System development methodology that is usually created or proposed by:
- Book Author
- Researcher
- Consultant
- House System
- Software factory
algorithm is: Sort-order the procedure to solve a problem
System Development Methodology is classified into 3 groups:
- Functional Decomposition Methodologies (Functional Methodology fission) HIPO (Hierarchy Input Process Output), SR (Stepwise Refinement), Isr (Iterative Stepwise Refinement), Information Hiding
- Data Oriented Methodologies (Data Oriented Methodology) Data Flow Oriented Methodologies: SADT, Composite Design, SSAD Data Structure Oriented Methodologies: JSD, W / O
- Prescriptive Methodologies ISDOS, PLEXSYS, PRIDE, spectrum
Classification of development methodology
• Functional decomposition
– Emphasizing the breakthrough system subsystem
– Example : HIPO, Stepwise refinement, iterative stepwise refinement, information hiding
• Data-oriented
– Emphasizing on the characteristics of the data processed
• Data-flow oriented: modules according to the type of data elements
• Data-structure oriented: structure of the input and output
• Prescriptive
– Usually provided by the manufacturer of the software
Development Tools And Engineering System
Can be:
1. Graphic HIPO, DFD, SADT, W / O, JSD
2. Chart
- Chart to describe the activity
- Chart to describe the layout
- Chart to describe the relationship of personnel
Techniques used for the development of the system include:
- Engineering Project Management: CPM, pert
- Technical Fact Finding: Interview, Observation, questionnaire, Sampling
- Engineering Cost Analysis
- Technical Running Meetings
- Technical Inspection
The cause of the failure of the system:
- Lack of adjustment of system
- Failure to set the user needs and involving users
- Less than perfect quality evaluation and cost analysis
- The existence of damage and error design
- The use of computer technology and software do not planned
- and the technology is not appropriate
- Development of systems that can not be kept
- Implementation of a poorly planned and implemented
It is used:
- SDLC
- Prototype
- Device modeling
- Engineering Project Management
- CASE
- JAD
- The involvement of the
Techniques used in the development a system
• Technical project management
Technique that is used to scheduling project, for example : CPM dan PERT
• Fack finding technique
to collect data and determine and find the facts
– interview
– Observation
• cost-benefit or cost-effectiveness analysis
• Technical meetings run
• walkthrough
Analyst System and programmer
Systems analyst is a person who analyzes the system with learning
problems that arise and determine the needs of users and
identify solutions that reasonless (better understand the aspects
business and computer technology).
Other names: system designers, business Analyst, systems consultant, systems
engineer, software engineer, systems programmer Analyst, information system
engineer.
Programmer who is writing code for an application program
based on a design made by the system analysts (better understand
computer technology).
Duties and responsibilities:
System analyst:
- Analyst responsibility system not only on making a computer program, but the system overall.
- Knowledge systems analyst must be knowledgeable, not only in computer technology, but also in the field of application
- Systems analyst job in making the program limited to the solution outline the problem.
- System analyst working relationship involving many people, not limited fellow analyst on the system, but also the programmers and system managers.
Programmer:
- Responsibility limited to the programmer making a computer program.
- Knowledge is quite limited to programmers computer technology, the system computers, utilities and languages program is required.
- Programmers job is technical and must be appropriate in the making program instructions.
- Programmers do not work the relationship with people, limited on fellow programmers and system analysts who prepare building design (specification) of the program.
Knowledge and skill system analyst
Systems analyst must have a broad knowledge and expertise that is needed. Some analysts agree that the knowledge-knowledge and expertise is necessary for following a good system analyst:
a. Knowledge and technical expertise on data processing, technology
computer and computer program
Technical expertise is to be held, including expertise in
the use of tools and techniques for developing software applications
and expertise in using computers.
Technical knowledge should include knowledge of the owned
hardware, data communications technology, computer languages,
operating system, Utilities, packages and other software.
b. Knowledge about business in general
Business application is an application that is now most widely applied,
the systems analyst must have knowledge about this. Knowledge
This is required so that the system analyst can communicate with users
system. Knowledge of this business include financial accounting,
cost accounting, management accounting, management control system,
marketing of production, personnel management, finance, organizational behavior,
company policy and business aspects of the other.
c. Knowledge of methods kuantitatip
In building models of applications, many analysts use the system
quantitative methods such as linier programming, dynamic programming,
regresion, network, decision tree, trend, simulation.
d. Experts solve complex problems into smaller problems
Systems analyst must have the ability to put the problem -
complex problems faced by the business, split problem
to the part-part, and then must analysis string can return to a system that can overcome
the problems are.
e. Experts to communicate and build relationships
Systems analyst must have the ability to make good communication
verbally and in writing. Expertise is required in the interview,
presentations, meetings and preparing reports.
f. Understand information systems development methodology
Human factors that are critical in the system and the human character
with each other differently. Analysts in the rigid system that builds
working relationship with other personnel, personnel involved, will
create jobs to be ineffective. Moreover, if the systems analyst
can not build a good relationship with the system, it will be
do not get support from the system or the management and
tendency of the system will hard.
Team development of the system (I)
System development project in the small and simple, it is possible only
there is a system analyst programmer as a trap (analyst / programmer)
or a double as the programmers systems analyst (programmer / analyst).
However, the development project for a large system or complex,
This work is usually done by people in the form of a team.
Members of the team developing this system depends on the size of the
the scope of the project will be treated. The team in general can be
of personnel, personnel as follows:
1. Manager analyst system (manage systems of Analyst)
Manager systems analyst is also known as project coordinator and
have duties and responsibilities as follows:
a. As a coordinator or head of the team developing the system
b. Direct, control and manage the system development team members
another.
c. Make a schedule of the project development system that will
done.
d. Responsible for defining the problem, feasibility studies, design
system and application.
e. Provide recommendations system.
f. Represent the team to deal with the system in terms of
negotiations-negotiations and the provision of advice-giving to
management and system users.
g. Create reports of project progress (progress report).
h. Reviewing and re-examine the work of the team.
2. Chairman of the systems analyst (systems Analyst leads)
Chairman of the systems analyst is usually served as deputy manager of the analyst
system. Duties of the task is to help managers and system analysts
represent the system when the manager obstruction analyst.
3. Senior systems analyst
Senior systems analyst (senior systems Analyst) is a systems analyst
that have been experienced.
4. Junior systems analyst (systems Analyst junior)
Analysis system is a junior systems analyst who has not experienced
still need assistance and guidance-systems analyst from a more
senior. Junior systems analyst is often also called the system analyst
still trained (systems Analyst trainee).
5. Senior application programmers (senior applications programmer)
Programmers Application is a senior computer programmer who has
experienced with the task of design specifications from the application program
and coordinate the work of other programmers. Application programmer
senior sometimes also referred to the programmer / analyst.
6. Application programmer (application programmer)
Application programmers are computer programmers are experienced enough
duty and can do without having to be directly again.
7. junior application programmers (junior applications programmer)
Application programmers junior is a computer programmer who has not
experienced and are still under the direct guidance from the programmer
more senior. junior application programmers are usually only involved in the
modules making a simple program, such as making
forms of I / O. Application programmer junior is often called
with the application programmer who still trained (applications programmer
trainee).
Team development of the system (II)
1. User System
a. Users
As end-user (operator) and the user-manager who oversees the work
end-user.
b. Management
Hold role in agreeing the development plan system
and the provision of funds.
2. System Designer
a. Project Coordinator
Responsible so that the team can work in harmony and optimal
and control the implementation so that appropriate plans.
b. System Analyst & Design
Personnel who provide solutions and designing the new system.
c. Programmer
Personnel who create programs based on design the system analyst.
d. Network Designer
Responsible for network design, such as LAN, MAN, WAN.
e. Technician (Hardware)
Personnel configuration-set the hardware configuration appropriate
in order to work optimally.
f. Database Administrator
Personnel responsible against a database system, covering
pattern data structure, data integrity, rights to provide access to the user,
backup, recovery and optimizing database performance.
g. Documenter
Personnel who make the system documentation, the book covers the operational
applications, and technical systems.
h. Software Tester
Personnel who ensure that the application programmer who created
according to specifications.
i. Graphic Designer
Personnel who have expertise in designing for applications based
GUI (Graphic Interface).
References
http://en.wikipedia.org/wiki/Waterfall_model
www.klasiber.net/file.php/1/PSI_I.pdf
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