WBS Structure

Multiple WBS structures are also convenient for when the Client requires his own WBS Structure while for resource leveling considering WBS Structure priorities a different structure is what makes sense, of course in addition to other settings.

Hi Jean-Yves,

please explain why Contract breakdown structure is parallel to zones, products and activities and what do you mean by parallel?

Other structures may include Responsibility, Geography, Types of work, etc.

Why do you try to restrict the number of activity structures?

We have more than 20 years experience of using multiple WBS and their types and number depend on project sprecifics, organization and responsibility structures, reporting and analysis requirements.

The WBS must be multi-dimensional.

There are three main tree structures that are mixed: "Activities are deployed on Products that are sometimes instanciated, and then assigned into a Zone."

The 3 dimensions are :

• Zones (ZBS, group of Products)
• Products (PBS, including functional systems)
• Activities (ABS, actions, processes that build the Products)

Others tree structures are parallel to these three main structures: Contract, Disciplines, etc.

I call this method which allows to build good quality schedule (very structured) "3D WBS method".

In this method, the WBS goes up to the tasks (that are NOT activities).

More details here: http://3d-wbs.blogspot.fr/

BR, Jean-Yves Moine

It is a lie there is a single best WBS Structure, the only correct way is to have several WBS Structures or Dictionaries.

The Clients have their particular preferences, the contractor also have his own needs and frequently different to the needs of the many clients.

Low quality software provides for only a single WBS Structure for individual projects as well as a single Portfolio Breakdown Structure in case of Portfolios.

Be aware that in the literature some authors give wrong advise about WBS Structure, one that comes to my mind is the insistence of segregating the same activity into separate deliveries just because no two contractors or no two managers shall share an activity or a deliverable.

• It is not uncommon for several managers to share responsibility of the same activity as in the case of multiple shifts. A single activity might have several crews each with their particular sets of meeting resources while the several crews might work independent of each other. 
• If you split the activity then it might happen that the resource leveling will not work as needed by scheduling the activities to occur at different times in case of shared resources that must work together.  
• Splitting an activity because of different shifts does not makes sense, you do not split an activity by the hour because some crews work on it during the week-end and others during different hours of the day, all can contribute to the progress of a single deliverable at different rates, different planned production rates as well as different actual production rates.

The PMI as well as most US specifications call for this wrong practice as if a good practice. Do not believe everything because it was written on a book, very frequently those who write the books are in error.