The PMI’s PMBOK defines a project as:
a temporary endeavor, with a beginning and an end, undertaken to create a unique product, service or result.
The project ends when the goals are achieved (the product, service or result is completed), when the goals cannot be achieved or they are not needed anymore.
To create the project’s product, service or result, we need to perform a series of activities, grouped into 47 processes. Each process has its own inputs, techniques, tools and outputs. These 47 processes are grouped into 5 process groups:
- Monitoring and Controlling
These 5 process groups are listed in a logical order as per the project’s phases.
- Human Resources
So this means that each one of the 47 processes belongs to only one process group and only one knowledge area simultaneously.
Given that I’ve worked in the software industry for 8 years and I’m familiar with software development lifecyles, I would compare the PMI’s PMBOK process groups and knowledge areas with the Unified Process’ phases and disciplines. For more about this comparison, I’d recommned the following article: Standards, compliance, and Rational Unified Process, Part I: Integrating RUP and the PMBOK
In the software industry, a typical project goal is to create a new information system for a customer. Depending on the requirements complexity the information system must cover, it may take up to 6, 12, 36 or more months to be completed. Usually, the requirements may have changed by them or the customer may not need it anymore. Also, a “test period” is very commong in the software industry. We usually build information systems for our customers as the end result of a project. Given the complexity of software systems, testing is very important and a testing the system in the real world for, let’s say 3 months after “project closing”.