The incremental build model is a method of software development where the model is designed, implemented and tested incrementally (a little more is added each time) until the product is finished. It involves both development and maintenance. The product is defined as finished when it satisfies all of its requirements. This model combines the elements of the waterfall model with the iterative philosophy of prototyping.
The product is decomposed into a number of components, each of which are designed and built separately (termed as builds). Each component is delivered to the client when it is complete. This allows partial utilisation of product and avoids a long development time. It also creates a large initial capital outlay with the subsequent long wait avoided. This model of development also helps ease the traumatic effect of introducing completely new system all at once.
There are some problems with this model. One is that each new build must be integrated with previous builds and any existing systems. The task of decomposing product into builds is not trivial either. If there are few builds and each build degenerates this turns into Build-And-Fix model. However if there are too many builds then there is little added utility from each build.
Steps 1.Requirements: This defines needed information, function, behavior, performance and interfaces. 2.Design: Data structures, software architecture, interface representations, algorithmic details. 3.Implementation: source code, database, user documentation, testing. 4.Test 5.Installation 6.Maintenance
Characteristics 1)Combine elements of linear and parallel process flow. 2)Incremental process flows apllied sequence ina staggered fashion as calendar time progresses. 3)Decomposed into a number of components, each of which are designed and built separately
Strengths 1)Focus on the delivery of an operational product with each increment. 2)Provide clients flexibility in making their decision. 3) Customer’s confidence is high as they validate every increment and provide feedback
Weaknesses 1) Needs good planning and design. 2) Needs a clear and complete definition of the complete system before it can be broken down and built incrementally. 3) Integration needs are very high
Applicability 1)Core product is well received and additional staff can be added to implement. 2) project which have lengthly development schedule. 3)Essential pars of the Rational Unified Process.