-System Development is a set of activities used to build an information system. A system is a component that interact to achieve a common goal. Information system (IS) is a collection of hardware, software, data, people, and procedures that work together to produce quality information. system development activities are grouped into phases, collectively called the system development life cycle (SDLC)
System Development:-
They are five processes in system development which are Planning, Analysis, Design, implementation, operation support, and security.
1) Planning
- Review project request
- Allocate resources
- From project development team
- Select a correct team
2) Analysis
- Analyse idea and concepts from planning phase and determine the best.
- study current system of the idea
- Determine user requirement
3) Design
- Acquire hardware and software
- Develop details of system
- Create prototype
4) Implementation
- Install/ build the system
- Train users
- Improve prototype if needed
5) Operation, support, and security
- Perform maintenance activities based on schedule
- Monitor system performance
- Maintain and update system security every week if needed.
-General guidelines for system development are:-
- Group activities or task into phases
- Involve users
- Define standards
-Project management is the process of planning, scheduling, and then controlling the activities during system development which mostly aim at Project scope, required activities, time estimates for each activity, cost estimates for each activity, order of activities, and activities that can take place at the same time.
1) Gantt chart is a popular tool used to plan and schedule the time relationships among project activities.
2) PERT (program evaluation review technique) chart is a project management tool used to schedule, organize and coordinate tasks within the project.
-Feasibility is a measure of how suitable the development of the system will be to the organization. In a term of:-
- Operational feasibility
- Schedule feasibility
- Technical feasibility
- Economic feasibility
-Documentation is the collection and summarization of data and information.
Techniques used by the members of the project team to gather data and information during system development:-
1) Review documentation.
2) Observe.
3) Survey.
4) Interview.
5) JAD (joint application design) session.
6) Research.
-System development project is required when:-
1) A user may request a new or modified system.
2) Organisation wants to improve hardware, software or other technology.
3) Situations beyond an organization's control might require a change.
4) Management might mandate a change.
5) A user may request a new or modified information system using a request for system services or a project request.
Activities that involve during the phases of system development life cycle: -
-Planning Phase is for a project begins when the steering committee receives a project request. Four major activities are performed is:-
1) Review and approve the project request.
2) Prioritize the project request.
3) Allocate resources.
4) From a project development team.
-Analysis phase consists of two major activities that are performed:-
1) preliminary investigation is to determine and defines the exact nature of the problem or improvement as well as interview the user who submitted the request.
2) perform the detailed analysis is to study of current system works where it determines the user's wants, needs, and requirements and recommend a solution.
Tools that used for Analysis phase are:-
- Process modeling - is an analysis and design technique that describes processes that transform inputs into an output. under process modeling we get three processes which are:-
ii) Data flow diagram (DFD) is a tool that graphically shows the flow of data in the system.
iii) Project dictionary contains all the documentation and deliverables of a project. Style of writing is structured English.
- The decision table is a table that lists a variety of conditions and the actions that correspond to each condition. Decision tree also shows conditions and actions, but it shows them graphically.
- The data dictionary stores the data item's name, description, and other details about each data item.
- Object modeling combines the data with the processes that act on the data into a single unit, called an object.
- UML (unified modeling language) has been adopted as a standard notation for object modeling and development where two diagrams include which is use case diagram and class diagram.
- The class diagram is a graphically shows classes and subclasses in a system. In the class
diagram. we have the inheritance to inherit methods and attributes of higher levels. The steering committee will discuss the system proposal and decides which alternative (Packaged software, Custom software and outsourcing) to pursue.
-Design Phase consists of two major activities which are acquired hardware and software and develop all of the details of the new or modified information system. The step is :-
- Identify technical specifications
- Solicit vendor proposals
- Test and evaluate vendor proposals
- Make a decision
The next step is to develop detailed design specification where sometimes called a physical design:-
- Database design
- Input and output design
- Program design
After that, a prototype will be created with the help of :
1) Computer aided software Engineering (CASE) tools are designed to support one or more activities of system development which contain: -
- Project repository
- Graphics
- Prototyping
- Quality assurance
- Code generator
- Housekeeping
-Implementation Phase is to construct the new or modified system and then deliver it. The implementation involves :-
- Develop Programs
- Install and test the new system
- Train users
- Convert to the new system
The program development life cycle follows these steps:
- Analyze the requirements
- Design the solution
- validate the design
- Implement the design
- Test the solution
Various test performed:-
- The unit test verifies that each individual program or object works by itself.
- System test verifies that all programs in an application work together properly.
- Integration test verifies that an application works with other applications.
- Acceptance test checks the new system to ensure that it works with actual data.
-Training involves showing users exactly how they will use the new hardware and software in the system, were it have three training which is:-
- One-on-one sessions
- Classroom-style lectures
- Web-based training
Operating, support and security phase is to provide ongoing assistance for an information system and its users after the is implemented.
There are three processes in this system:-
1) Perform maintenance activities - to maintain the lifetime of the system.
2) Monitor system performance - to see id any improvement is needed.
3) Assess system security - manage the security and keep it updated.
Computer security plan should have;-
1) Identify all information assets of an organization.
2) Identify all security risks that may cause an information asset loss
3) For each risk, identify the safeguards that exist to detect, prevent and recover from a loss.
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