Prescriptive Process Models
The name 'prescriptive' is given because the model prescribes a set of
activities, actions, tasks, quality assurance and change the mechanism for
every project.
There are three types of prescriptive process models. They are:
1. The Waterfall Model
2. Incremental Process model
3. RAD model
The Waterfall Model
The waterfall model is also called as 'Linear sequential
model' or 'Classic life cycle model'.
In this model, each phase is fully completed before the beginning of the
next phase.
This model is used for the small projects.
In this model, feedback is taken after each phase to ensure that the
project is on the right path.
Testing part starts only after the development is complete.
Advantages of waterfall model
, The waterfall model is simple and easy to understand, implement, and
use.
All the requirements are known at the beginning of the project, hence it is
easy to manage.
It avoids overlapping of phases because each phase is completed at once.
This model works for small projects because the requirements are
understood very well.
This model is preferred for those projects where the quality is more
important as compared to the cost of the project.
Disadvantages of the waterfall model
This model is not good for complex and object oriented projects.
It is a poor model for long projects.
The problems with this model are uncovered, until the software testing.
The amount of risk is high.
Incremental Process model
The incremental model combines the elements of waterfall model and
they are applied in an iterative fashion.
The first increment in this model is generally a core product.
Each increment builds the product and submits it to the customer for any
suggested modifications.
The next increment implements on the customer's suggestions and add
additional requirements in the previous increment.
This process is repeated until the product is finished.
For example, the word-processing software is developed using the
incremental model.
The name 'prescriptive' is given because the model prescribes a set of
activities, actions, tasks, quality assurance and change the mechanism for
every project.
There are three types of prescriptive process models. They are:
1. The Waterfall Model
2. Incremental Process model
3. RAD model
The Waterfall Model
The waterfall model is also called as 'Linear sequential
model' or 'Classic life cycle model'.
In this model, each phase is fully completed before the beginning of the
next phase.
This model is used for the small projects.
In this model, feedback is taken after each phase to ensure that the
project is on the right path.
Testing part starts only after the development is complete.
Advantages of waterfall model
, The waterfall model is simple and easy to understand, implement, and
use.
All the requirements are known at the beginning of the project, hence it is
easy to manage.
It avoids overlapping of phases because each phase is completed at once.
This model works for small projects because the requirements are
understood very well.
This model is preferred for those projects where the quality is more
important as compared to the cost of the project.
Disadvantages of the waterfall model
This model is not good for complex and object oriented projects.
It is a poor model for long projects.
The problems with this model are uncovered, until the software testing.
The amount of risk is high.
Incremental Process model
The incremental model combines the elements of waterfall model and
they are applied in an iterative fashion.
The first increment in this model is generally a core product.
Each increment builds the product and submits it to the customer for any
suggested modifications.
The next increment implements on the customer's suggestions and add
additional requirements in the previous increment.
This process is repeated until the product is finished.
For example, the word-processing software is developed using the
incremental model.
