Evolutionary model in software engineering

Evolution development model :

Evolution development is based on the idea of developing an initial implementation,exposing this user comment and refining it through many versions until an adequate system has been developed.

Evolutionary model is also referred to as the successive version model,and sometimes as the incremental model.In Evolutionary model,the software requirement is first broken down into several modules (or functional units) that can be incrementally constructed and delivered.The development first develops the care modules of the system.The core modules are those that do not need services from the other modules. The initial product skeleton is refined into increasing levels of capability by adding new functionalists in successive version.

It is combination of iterative and incremental model of software development life cycle.

Here V1 = version 1

V2 = version 2

V3 = version 2

The evolutionary module is normally useful for very large products,where it is easier to find modules for incremental implementation.

Concurrent activities

Advantage of EDM (Evolutionary Development Model ) :

1) evolutionary model is normally useful for very project.

2) User gets a chance to experiment with a partially development software much before the complete version of the system Is released.

3) Evolutionary model helps to accurately elicit user requirements during the delivery of different versions of the software.

4) The core modules get tested thoroughly,Thereby reducing the chances of errors in the core modules of the final products.

Some good attribute of a software product

Disadvantage of Evolution development model :

1) Sometimes it is hard to divide the problem into several version that would be acceptable to the customer which can be incrementally implemented.

2) The process is not visible .Managers need regular deliverable to measure progress.It system are developed quickly.It is not cost effective to produce documents that reflect every version of the system.

3) System are often poorly structured continual change tends to corrupt the software structure incorporating software changes becomes increasing difficult and costly.

Others Disadvantage of Evolution development model

1) Uncertain nature of customer needs : A confused user has uncertainty over his requirements , so giving him several version may change his requirement rapidly.

2) Time and cost : This model reduce time and cost but requirements is not gathered correctly . It will subsequently time ,cost and effort .

3) Confuse by several version: An user might get confused by several version of the software . It will effect on the final product.

Types of Evolution development model

There are two fundamental types of Evolution development model .

1) Exploratory development : The object of the process is to work with the customer to explore their requirements and deliver a final system.the development starts with the parts of the system that are understood. The system involves by adding new feature proposed by the customer.

2) Throwaway Prototyping : Where the objects of the evolutionary development process is to understand the customers requirements and here develop a better requirements definition for the system. The prototype concentrate on experimenting with the customer requirements that are poorly understood.