The WBS Development Process

A WBS Development Case Study

In this session I'm going to illustrate the process of developing a work breakdown structure with an example.

We're going to develop a WBS for an electric vehicle concept car. We can't go through the entire project because it's a huge undertaking. What we will do is develop fragments of the WBS to demonstrate core planning concepts.

4 Steps for WBS Development

WBS development can be broken down into four main steps:

  1. Naming the project
  2. Identifying the deliverables
  3. Specifying the services required to produce those deliverables and
  4. Creating the work packages for assignment to project team members.

The last three steps are repeated constantly throughout the project as we develop a more detailed knowledge of the end product.

Naming the Project

At the beginning of any project we're always faced with a blank page. It's sometimes really hard to get started. The only thing we have is a project charter provided by management. We're instructed to go ahead and develop an electric vehicle concept car. We're authorised to spend $20 million and we've got two years to roll out our first vehicle.

So where do we start? Well at least we can name the project: "Electric Vehicle Concept Car Project" (EV for short).

Right! We've defined level one of our WBS!

Identifying the Deliverables

The next step is specifying exactly what we're going to deliver. That's easy, where delivering an EV concept car. Beyond that we have a problem; we don't know. So to further develop the breakdown of the deliverable we need to do some engineering.

Specifying Services

Systems engineering will be our first service to the project. The first thing we'll have to do is develop the overall product concept. Our engineers and marketeers will form an Integrated Product Development Team to identify the target market; who will buy the vehicle and why.

They'll conjure up use scenarios and figure out basic requirements such as:

  • Vehicle range
  • Passenger capacity
  • Top speed
  • Fuel economy
  • Constraints on tail pipe emissions and of course
  • The target retail price.

All this will be recorded in an Electric Vehicle Concept Document.

The engineers will then take this document, develop alternative designs, make design trade-offs and document design decisions in a Preliminary Design Description.

Fundamental design decisions might include:

  • Power source: is the vehicle a hybrid or is it all electric.
  • Is it a plug-in? Can we recharge the vehicle overnight from a power outlet in our homes?

They'll make decisions on drive train design - for example with a hybrid they'll choose between :

  • The serial approach where the electric motor drives the wheels or
  • The parallel approach where an internal combustion engine or the electric motor can provide direct drive.

Evolving the WBS

From a standing start this is about as far as we can go with our plan. We'll need a clearer review of the end product before we can plan in greater detail. This illustrates the reality that no WBS can be completely elaborated on day one. They all evolve over time.

But right now some work CAN be done. We can generate two work packages, one for the concept document and the other for the preliminary design. Each of these packages will lay out activities, schedules and resource requirements in further detail. They'll give clear direction to our development teams.

About this talk

Everyone agrees that the work breakdown structure (WBS) is a useful project planning tool but approaches to building them vary widely. In this talk Les Chambers uses a simple four step process to demonstrate core WBS development concepts. Using the development of an electric vehicle concept car as a case study.

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