Multiple Openings in Mphasis

Multiple Openings in Mphasis

Company: Mphasis Limited
Openings: Multiple positions

V-model in software testing with advantages and disadvantages

V model

V-model is software development model it is improve from the waterfall model. V-model is normally used for manage the software development project in the large company.

V-model is also called verification and validation model (V&V). It has a very intensive testing in order to eliminate the bug/error that may be occur during each stage of development project using V-model.

You can see the picture of V-model as below

Prototype Model or Pilot Model in software Testing

Prototype Model (Pilot Model)

Prototype module is just a demo application to show client, who does not belongs to the IT sector. It just to show how the application looks after completion whether he wants any changes or as it is.

•         I.            Prototype is a working model of software with some limited functionality.
•       II.            The prototype does not always hold the exact logic used in the actual software application and is an extra effort to be considered under effort estimation.
•     III.            Prototyping is used to allow the users evaluate developer proposals and try them out before implementation.
•     IV.            It also helps understand the requirements which are user specific and may not have been considered by the developer during product design.

Following is the step-wise approach to design a software prototype:

Spiral Model with its Advantages and Disadvantages

Spiral Model

In spiral model the project will be in parts.

The process begins at the center position. From there it moves clockwise in traversals. Each traversal of the spiral usually results in a deliverable. It is not clearly defined what this deliverable is. This changes from traversal to traversal. For example, the first traversals may result in a requirement specification. The second will result in a prototype, and the next one will result in another prototype or sample of a product, until the last traversal leads to a product which is suitable to be sold. Consequently the related activities and their documentation will also mature towards the outer traversals. E.g. a formal design and testing session would be placed into the last traversal.

These regions are:

§  The planning task - to define resources, responsibilities, milestones and schedules.

§  The goal determination task - to define the requirements and constraints for the product and define possible alternatives.

§  The risk analysis task - to assess both technical and management risks.

§  The engineering task - to design and implement one or more prototypes or samples of the application

                The most outstanding distinction between the spiral model and other software models is the explicit risk evaluation task. Although risk management is part of the other processes as well, it does not have an own representation in the process model. For other models the risk assessment is a sub-task e.g. of the overall planning and management. Further there are no fixed phases for requirements specification, design or testing in the spiral model. Prototyping may be used to find and define requirements. This may then be followed by "normal" phases as they can be found in other process models to handle design and testing.

The advantages of the spiral model are that it reflects the development approach in many industries much better than the other process models do. It uses a step-wise approach which e.g. goes hand in hand with the habit of maintaining a number of hardware sample phases in cases where the product to be produced is not only software for a given environment, but also contains the development of hardware. This way the developers and the customer can understand and react much better to risks in the evolutionary process. By having an iterative process which reduces formalism and omit-table activities in the earlier phases the use of resources is optimized. Further, any risks should be detected much earlier than in other process models and measures can be taken to handle them.
                The disadvantages of the spiral model are that the risk assessment is rigidly anchored in the process. First of all it demands risk-assessment expertise to perform this task and secondly in some cases the risk assessment may not be necessary in this detail. For completely new products the risk assessment makes sense. But I dare to say that the risks for programming yet another book keeping package are well known and do not need a big assessment phase. Also if you think of the multitude of carry over projects in many industries i.e. applying an already developed product to the needs of a new customer by small changes, the risks are not a subject generating big headaches. Generally speaking the spiral model is not much esteemed

E.g. if 1st application is developed it will tested and sent to client. This is suitable for very large project.

Advantages:-

1. Requirements are updated.

2. If changes made in one module it not affects the other module.

3. There will be better understanding between client and company.

4. There will be better quality.

Disadvantages:-

1. Requirements are not tested.

2. Design is not tested.

3. Root course analysis.

4. Cost of fixing the defect s high.

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