Demerits Of Water Fall Model

Published Date: 02 Nov 2017

Introduction:

Task-1:

(a): Waterfall Model:

It is a very useful model which is widely used and it’s easy to understand, it’s a sequential design process which is flowing steadily downwards like water. It is a step by step process, if we will find any error so we would check from backward instead of directly going to that point of error. The following diagram shows the steps.

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Analysis and Gathering Requirement:

In this first step of waterfall model, the developer has to conduct a meeting with the costumer to know about his requirement for the software. He discusses the things in details and analyzes the whole project system and then collects requirements based on software development.

System Design:

In this stage based on the requirements he has collected, he will make a rough model so that the software process becomes easy for implementation. After this stage they would have documentation so that it would be easy for the user to understand.

Detailed Design and Coding:

In this step the developer will make an actual model of software. The developer sees the problems in details. And if there is any error they would check and correct that which is also called coding.

Testing:

After implementation the developer sees the software weather it is working properly or not then he will do the testing.

Delivery:

In this last steps the developer hand over the project to the user.

Merits of Water Fall Model:

This model is easy to understand for the user.

It is good for small projects where requirements are well understood.

Waterfall model is preferred in projects where quality is more important than schedule or cost.

Demerits of Water Fall Model:

It is costly and time consuming.

If we want any change we have to go from below so it’s difficult.

Not suitable for difficult or moderate projects.

(b) Some of the models that don’t have specific structures are:

Code and fix:

It’s very easy and simple kind of model and consists of two steps.

a) Write coding to the program

b) Fixing the problem in that code

This model is very simple as it doesn’t need any proper team work, and each one would not be able to convince his point to the others so it saves time by fixing errors in the early ages.

Merits of Code and fix:

Less time taking.

Easy to use.

Good for small projects as risk is reduction.

Demerits of Code and fix:

It’s difficult to detect the errors.

No time limits.

Difficult for large projects.

Rapid prototyping:

In this model the costumers are not familiar with the software so they don’t know what kind of program they actually want.

Merits of Rapid Prototyping:

Less chances of risk of incorrect user requirement.

It’s a user friendly.

Demerits of rapid prototyping:

The developer only can make the project for just one company.

Very expensive.

3) Cots: (Commercial off-The Shelf Software)

This is the easiest and cheapest model. In this model the developer takes the model which is already exist and they make changes in that model only according to the user requirement.

Merits of cots:

Well worked model.

Has to make changes minor.

Demerits of cots:

1) When we put it on internet, we face problem because the internet ask for the security code.

Agile:

This model is used for companies only. In this model, the developer wants the team for the other skills to complete the project. Communication must be there with the client. It is easy for the developer to make changes in the software from start to the end. The developer gives all the updates to the client about the software.

Merits of Agile:

It is easy to make small projects.

Main aims to final product.

The company can test for a good result in every week.

Demerits of Agile:

It is difficult to make large projects.

We need proper planning and documentations.

If the program will make in pairs then it will be costly.

1.2) (a) SDLC (System development life cycle):

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The System Development is consists of the following stages:

1. Preliminary Investigation:

The developer has to spend for days to understand the problem; he can install the proper system. In this stage, the developer collects all the information available for the system which they need and he is also gathering the whole workers with him to collect the requirements for the system.

2. Analysis of the Requirement:

The developer understands the information and functions of the software which all he requires for the system. He briefly goes through the requirements and to develop the performance of the system. He also wants to get more information and resources to build the suitable system.

3. System Design:

The developer makes rough designs on paper or on the computer, to check whether the rough image of system includes all the requirements or not. Once this stage done, then he will choose and finalizes the suitable designs for the development of the system.

4. System Coding:

The developer translates the code or the program in machine language so that it can be readable easily. The coding step is time spending and it has many errors.

5. System Testing:

Once the programming stage done, then he tests the systems whether it is working according to the client’s needs or not. And he corrects the error if there are any.

6. System Implementation:

This is the most important phase. In this stage the developer finally gives the system to the client and expecting for a positive response.

7. System Maintenance:

In this last stage, the developer wants to maintain the system and checks whether it’s working in the way he made it or not. Then he again maintains the system by removing the defects of flaws if happened.

1.2) (b) Rapid Prototyping:

I would prefer to rapid prototyping life cycle model to develop software for university works because it is one among the easiest and user friendly model. It does not require any team work. Even for the non technical management it will be easy to understand. At each stage of development the progress details has to submit to the management. Here instead of presenting report we submit rough model. It will be more convenient as the management could see the development physically rather theoretical documents.

In universities any time there could change system or introduction of new courses. So if the management demands change in the software developing in the middle also it can be done easily. It indicates advantage over other models because complex models like water fall or spiral if user demands changes it will be great loss because they have to follow step by step procedure and then make changes. It will consume more time and cost high. As this model is completely customer oriented they’ll proceed only after the management finds satisfaction