Week 2 - The Context Of Systems Analysis And Design

       This week gave me a deeper understanding of the context of systems analysis and design. We first look at the activities that take place in the Systems Development Life Cycle in great detail. Firts and foremost what do we mean by SDLC??? The systems development Life Cycle refers to a project management technique that divides a complex project into smaller, more easily managable segments. Breaking down a project into many phases allows the managers to verify the successful completion of the different phases of the project before allocating resources to subsequent phases. From last week's lectures and resources, Systems Analysis and Design revolves around problem solving. For any project to be successful, regardless of if its a complicated IT system or a simple business system, the analyst MUST be able to draw a detailed plan to follow. To build a reliable, robust and efficient system, the team of analysts must have an organized, methodical sequence of activities.

         The Systems development Life Cycle outlines a series of phases that must be followed for a system to be successfully structured and yield desirable results. The seven phases of the SDLC are as follows:

1. The Planning Phase

2. The Analysis Phase

3. The Design Phase

4.  The Development Phase

5. The Testing Stage

6. The Implementation Phase

7. The Maintenance Stage

The planning stage is where the goals as well as the scope of the project are initially determined. Planning also produces a detailed project schedule and also confirms the feasibility of the project. The factors to be considered here are the costs incurred to ensure the project is financially viable, organizational and technical resources as well as the willingness of the staff to learn new concepts. The project therefore has to be well staffed right from the beginning.

The analysis phase involves gathering as much information as possible to understand the problem domain to be solved. This aims towards establishing the exact source of the problem. The system requirements are clearly defined and the prototypes necessary for the discovery of the requirements are also built. The requirements are prioritized and then later on, alternatives are generated and evaluated accordingly. Finally recommendations are reviewed with the management!

After all the problems have been identified we can design a system to solve these problems.Here we design and intergrate the network as well as the application arhitecture. Later the user interphases and the system intephases are also designed. A database is later designed and intergrated. First, the creation of a logical design will be undertaken and this will explain what the new system will do; the creation of a physical systems design will list the equipment needed to perform the logical design.

The development stage converts the deign specifications into executable computer programs. The programmers and other participants of the project discuss the design specifications of the project before the actual programming begins and this is aimed at ensuring that the programmers clearly understand the program designs ad functional requirements. In the development phase, the systems is built and programmed in a particular progamming language such as java, C++, VB.NET or any other language relevant to the system. Computer programmers will carefully do the coding to ensure a robust and efficient system is built to cater for the needs of the business involved. I also found out that there are 10 different types of testing tech

Once the systems has gone through the development stage it has to be thoroughly tested to eradicate errors and ensure the accuracy of the program codes used. Testers are people who identify the defects/weaknesses of a program during the process of testing.

Having eradicated all the errors in the testing stage, we embark on the implementation of the project. This is where the system is officially launched and later installed for use by the company. The support and maintenance phase then comes in where we make updates if the system and repair it just in case there is any problem encountered. We can also enhance the system by updating it to increase its capabilities. Users may also require a help desk or a support team so as to explain their problems to representatives of the system.

Different approaches may be used when building an I.T. system. There is the waterfall approach, the overlapping approach and the iteration approach. In the waterfal approach,  each phase into the next subsequent phase. The overlapping approach takes the assumption that the waterfall approach is not realistic and that we are not perfect.  Overlaps can be more frequent than waterfall. In iteration work activities are repeated and each iteration refines the previous result.  This approach assumes that nobody gets it right the first time and there is also a series of mini-projects for each iteration.

Methodologies and models are necessary in the process of systems development Life Cycle. Methodologies are comprehensive guidelines to follow for completing every SDLC activity and consists of a collection of models, tools and techniques. Models on the other hand are a representation of an important aspect of the real world but not same as real thing. Some models of a systems component are like data flow diagrams, flow charts, entity relationship diagrams, structure chart and class diagrams. 

Two approaches used in Systems Development are the traditional approach and secondly structured programming. The traditional approach is also called the structured systems development approach and it makes use of structured analysis and design techniques(SADT).  Strutured programming improves the quality of a computer program and allows other programmers to easily read through the code and modify the code work. Finally each program module has one begining and one ending as well.