Chapter 12

Chapter 12: Exploring Information System Development

System development is the development of an information system. System is a set of components that interact to achieve a common goal. System development should involve representatives from each department in which the proposed system will be used.
Information system is a collection of hardware, software, data, people and procedures that work together to produce quality information.

There are 5 phases in system development life cycle, below is the introduction of each phases:
1) Planning
- Review project requests.
- Allocate resources.
- Form project development team.
- Brainstorm idea and concept.
2) Analysis
- Analyse ideas and concepts from planning phase and determine the best.
- Study current system.
- Determine user requirement.
3) Design
- Acquire hardware and software.
- Create prototype.
- Develop details of system.
4) Implementation
- Install and test prototype.
- Train users.
- Improve prototype if needed.
5) Operation, Support and Security
- Perform maintenance activities.
- Monitor system performance.
- Maintain and update system security.

General guidelines for system development:
1) Group activities or task into phases.
2) Involve users.
3) Define standards.

Ongoing activities of system development:
A) Project management- process of planning, scheduling and controlling the activities during system development.
Mainly focus on areas such as:
1) Project scope.
2) Required activities.
3) Time estimates for each activities.
4) Cost estimates for each activities.
5) Order of activities.
6) Activities that can take place at the same time.
Software or tools used to help in project management:
1) Gantt chart- a popular tool used to plan and schedule the time relationships among project activities.
2) PERT (Program Evaluation Review Technique) chart- a project management tool used to schedule, organise and coordinate tasks within a project.

B) Feasibility- measure of how suitable the development of system will be to the organisation.
In terms of:
1) Operational feasibility- does it help in daily operation?
2) Schedule feasibility- can we meet the schedule requirement?
3) Technical feasibility- can we meet the technical requirements?
4) Economic feasibility- can it produce profit?

C) Documentation- the collection and summarisation of data and information.

D) Data and information gathering
Techniques used by 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 request a new or modified system.
2) Organisation wants to improve hardware, software or other technology.
3) Situation beyond controls of organisation may require change.
4) Management might mandate a change.
5) A user may request for a new information system using a request for system services or a project request.

Activities that involve during the phases of system development life cycle.
A) Planning
Four major activities that are performed:
1) Review and approve project requests.
2) Prioritise the project requests.
3) Allocate resources.
4) Form a project development team.

B) Analysis
Two major activities that are performed:
1) Preliminary investigation- determines and defines the exact nature of the problem or improvement as well as interview the user who submitted the request.
2) Perform detailed analysis- study of current system, determine the users' wants, needs and requirements and recommend a solution.
Tools that are used during analysis phase:
1) Process modeling (analysis and design technique that describes the processes that transform inputs into outputs) is done during the analysis phase and it consists of:
i) Entity-relationship diagram (ERD)- a tool that graphically shows the connections among entities (objects in a system that have data) in a system.
ii) Data flow diagram (DFD)- a tool that graphically shows the flow of data in the system.
iii) Project dictionary- contains all documentations deliverables of a project. Style of writing is structured English.
2) Decision table and decision tree.
i) Decision table- a table that lists a variety of conditions and actions that correspond to each condition. In table format.
ii) Decision tree- shows the conditions and actions graphically.
3) Data dictionary- stores the data item's name, description and other details about each data item.
4) Object modeling- combines data with the processes that act on the data into a single unit called object.
5) UML (Unified Modeling Language)- standard notation for object modeling and development.
Examples of diagram included in UML:
1) Use case diagram- graphically shows how actors (users) interact with the information system.
2) Class diagram- graphically shows classes and subclasses in a system.
Steering committee will discuss the system proposal and decides which alternative (packaged software, custom software, outsourcing) to pursue.

C) Design
Activities that are performed:
1) Acquire hardware and software
Steps:
i) Identify technical specifications.
ii) Solicit vendor proposals.
iii) Test and evaluate vendor proposals.
iv) Make a decision.
2) Develop all of the details of the new or modified information system
Involve:
i) Database design.
ii) Input and output design.
iii) Program design.
After that, a prototype (working model of proposed system) will be created.
With the help of:
1) Computer-aided Software Engineering (CASE)- tools that are designed to support one or more activities of system development.
It contains:
i) Project repository.
ii) Graphics.
iii) Prototyping.
iv) Quality assurance.
v) Code generator.
vi) Housekeeping.

D) Implementation
It involves:
1) Develop programs
Steps:
i) Analyse the requirements
ii) Design the solution.
iii) Validate the design.
iv) Implement the design.
v) Test the solution.
vi) Document the solution.
2) Install and test the new system
Various test performed:
i) Unit test- verifies that each individual program or object works by itself.
ii) System test- verifies that all programs in an application work together properly.
iii) Integration test- verifies that an application works with other applications.
iv) Acceptance test- check the new system to ensure that it works with actual data.
3) Train users
It involves showing users how to use the new hardware and software in the system by:
i) One-on-one sessions.
ii) Classroom-style lectures.
iii) Web-based training.
4) Convert to new system
Types of conversion strategies:
i) Direct conversion- directly convert old system to new system.
ii) Parallel conversion- converting old system to new system while still using old system.
iii) Phased conversion- converting old system to new system in various phase. For example, 70% usage on old system and 30% usage on new system for first phase. And 30% usage on old system and 70% usage on new system for last phase.
iv) Pilot conversion- rolling out new system for small group of users for testing and evaluation.

D) Operation, Support and Security
Activities that are performed:
1) Perform maintenance activities- to maintain the lifetime of the system.
2) Monitor system performance- to see if 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 organisation.
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.