ISTQB - Prototype Model

In last article we have understood about the spiral model, Now we will about to understand for Prototype model which is widely used for software development. This would be the last model of software development. In prototype model, we are creating the replica of the original product or application first which will be observed and identified deeply. After the engineering phase will be done for product or application, we are including clients here for their feedback on product replica. Here Design and coding is not directly applied but before that one prototype have been created which will give us the actual feel or the product or application and client will understood that properly and list down more requirements, updates and changes which needs to be note before the actual development.

Prototype model have the advantage that if customer is not aware with whole requirements in early stage still development can be started. In the image, its steps are given like Requirements, Design, Building prototype, Engineer product, Refining Prototype, Client Evolution. Now let’s understand each steps in details.

1. Requirements :

In this step, basic planning and basic requirements are discussed as per client’s suggestions and reviews. In this phase of prototype mode, security and performance of application will not be discussed in details. As here we are just planning for prepare replica of the original product.

2. Design:

In this phase, Very basic level requirements are designed for replica of product. Some user interface and features are introduced here for the product as per client requirements but it may possible that it will not be stay as expected internally so just look and feel will be identified in this phase and further as per the new changes and updates, internal development will be define. 

3. Building Prototype:

Actual building of the replica of the product will be started in this phase. As per the discussed requirements all loops and frameworks will be prepared here and then it will be shared with the client. After the approval of the client, further features will be introduced for building a product.

4. Engineer the Product:

After building the product, it is necessary to identified that whatever the framework and reporter we have used for the product is perfect or not. Will be okay for long term or it works for short time periods that all are define in this phase.

5. Refining Prototype:

This may be the last step for developing the replica of product. The final feedback and reviews or comments of the client have been discussed here. Even negotiation is applied by client in this phase. How much time will be required to develop a whole product and how estimation procedure will be taken place for different development team?  This all will be finalized. All changes and discussion will be shown to the client with the replica of original product and if they have agreed with the product replica then product development will take place otherwise new replica will be prepared as per above steps and again customer feedback will be taken till they will be satisfied with the requirement.

When to use prototype Model:

1. When interaction of the customer will be required more at that time this model can be used.
2. To develop an online product or websites, client communication is required often then prototype is best solution as we can gave them the replica of the product in very early stage and accordingly client can give their updates and changes which needs to be applied further in product.
3. In this model continuous interaction will be done with the customers so result of developed product will be always good as there are no chance of misunderstanding of requirements so we can say that this model is good for developing a human interface systems.

Advantages of Prototype Model:

1. If some functionality have been missed then it can identify easily in early stage.
2. Client’s feedback will be available for better solution of development of product.
3. As we are preparing replica of the product first then it is easy to identify errors in early stage.
4. As users are taking part in the development phase of the product, understating of that product will be increased.

Disadvantages of prototype model:

1. If planning will not done properly then by using this methodology we can leads to the failure 
2. Sometimes it may happen that complexity of the actual product will be increased due to more changes and updates of clients.