Project Management

Introduction to System Development

New information systems are developed when either an existing system no longer meet its users’ needs are identified that could be met by an information system.
The development of many information systems is substantially different to the development of most engineered systems.
The most fundamental differences are due to the nature of software as it being designed.
Software Development Life Cycle

The traditional structured approach to systems development specifies distinct stages and phases, combining to describe all the activities needed to develop an information system , this process is known as SDLC (Software Development Life Cycle)
Stages –
1. Understanding the problem
2. Planning
3. Designing
4. Implementing
5. Testing, evaluating and maintaining
Understanding the Problem

Understanding is the first stage for SDLC, determining the purpose and requirements of a new system.
This stage determines what needs to be done

Systems Analyst
A person, who analyses systems, determines requirements and designs new information systems.
A systems analyst is responsible for analyzing existing systems; determine requirements and then designing the new information systems.

Requirements
Features, properties or behaviors a system must have to achieve its purpose. Each requirement must be verifiable.
In general terms, a requirement is a feature, property or behavior that a system must have.
If a system satisfies all its requirements then the system’s purpose will be achieved.

Processes vs. Outputs

Activities (Processes)
Interview/survey users of the existing system.
Interview/survey participants in the existing system.
Prepare and use requirements prototypes.
Define the requirements for a new system.

Deliverables (Outputs)
User experiences, problems, needs and ideas.
Models of existing system including context diagrams and DFDs.
Requirements report stating the purpose and the requirements need to achieve this purpose.

Interview/Survey Users of the existing system

In most information systems, the purpose of the system is primarily concerned with fulfilling the needs of its users - users being the people who utilize the information created by the system.
Interviews and surveys are the primary tools for collecting user experiences and problems with the existing system, and also for identifying their needs and any new ideas they may have to improve the system.

Interview/Survey Participants in the existing system

Participants within existing systems will have an understanding of the part of the system with which they primarily interact. They are able to identify problems and often they also have ideas in regard to solving these problems.
Participants are a vital source of information in regard to the detail of the information processes occurring within the existing system.

Requirements Prototype

A working model of an information system, built in order to understand the requirements of the system.
Requirements prototypes model the software parts of the system with which the user will interact. The model is composed of screen mock-ups and perhaps sample reports.
Requirements prototype accurately simulates the look and behavior of the final application with minimal effort.

Define the requirements for a new system

The previous activities aimed to provide sufficient information to enable the creation of a complete set of requirements for the new system.
These requirements are expressed within a formal ‘Requirements Report’; this report is the most significant deliverable from the first stage of the SDLC.

How requirements reports are used during the SDLC

When planning, the Requirements Report is used to determine possible solution options and their feasibility. Different solutions can be compared fairly, as they all aim to achieve identical requirements.
Requirements Report is a blue print of what the system will do, as such it forms the basis of the contract between the