Project Life Cycles

There are main three life cycles classified by PMI in fifth edition of the PMBOK Guide ®

1) Predictive

 2) Iterative  and

 3) Adaptive

Predictive:

It is better known as “Waterfall” methodology or we can say it “Plan Driven” approach. In this method scope, time, cost of the required deliverable scope are defined in early stage of the Project. After that to achieve deliverable, Project flows in series of phases whether it is Sequential or Overlapping. Each phase has different type of task so skill set and project team may vary as per the phase. Waterfall model usually presented as following phases:

1. Analysis
2.  Requirements
3.  Design
4.  Construction
5.  Testing
6.  Deployment
7.  Maintenance

Each phase is completed before next phase start. If requirement does not change often then this model suit it fine. It normally best fit to organisation which have large number of junior developers.

Iterative:

To develop the Product, in this cycle project phases are intentionally repeated to achieve objective. Product development flows in the series of iteration of the phases. Product development grows as per iteration repetition. Each phase builds on deliverable of previous phase. System builds gradually through the incrementally repetition of phases. So, as per the system flows we can add new features and changes easily contrary to Predictive cycle. We can arrange lesson learn of each phase and improve the next phase as per the lesson learn.

Iteration 0	Iteration 1	Repeat as needed	Iteration n
Project Plan	Develop and Test	Develop and Test	Develop, Test and Release

Adaptive:
It is better known as “Agile” or “Change Driven” methodology. This method introduced to make development in different stages. It is same as Iterative or Incremental but the difference is that here iteration is small in weeks rather than in months. New changes can be accommodated easily and risks can be easily manageable.

Here, the scope of the Project is broken down in to the small chunks are known as “Product Backlog”. After finishing each iteration, customer review it to ensure that it is finished or not. Customer or Sponsor are continuously engaged to ensure deliverable. Customer no accept the incomplete or defective features.

We can prefer this cycle for Rapid application development environment, where requirement is not clear at initial level. The best example of this method is “Scrum”.

Developers and business people are closely related with each other. Customer is satisfied by fast delivery and Deliverable can be frequently deliver to customer.

It can be best fit to organisation which have large number of senior developers and small number of junior developers.

Above Iteration is repeated till the Product development.