THE W5HH PRINCIPLE

In an excellent paper on software process and projects, Barry Boehm [BOE96] states:
“you need an organizing principle that scales down to provide simple [project] plans for
simple projects.” Boehm suggests an approach that addresses project objectives, milestones
and schedules, responsibilities, management and technical approaches, and
required resources. He calls it the WWWWWHH principle, after a series of questions that
lead to a definition of key project characteristics and the resultant project plan:
Why is the system being developed? The answer to this question enables
all parties to assess the validity of business reasons for the software work. Stated
in another way, does the business purpose justify the expenditure of people, time,
and money?

What will be done, by when? The answers to these questions help the team
to establish a project schedule by identifying key project tasks and the milestones
that are required by the customer.
Who is responsible for a function? Earlier in this chapter, we noted that the
role and responsibility of each member of the software team must be defined.
The answer to this question helps accomplish this.
Where are they organizationally located? Not all roles and responsibilities
reside within the software team itself. The customer, users, and other stakeholders
also have responsibilities.
How will the job be done technically and managerially? Once product
scope is established, a management and technical strategy for the project must
be defined.
How much of each resource is needed? The answer to this question is derived
by developing estimates based on answers to earlier questions.
Boehm’s W5HH principle is applicable regardless of the size or complexity of a software
project. The questions noted provide an excellent planning outline for the project
manager and the software team.