I recently initiated an interesting discussion about product-based planning on LinkedIn. It started soon after I promoted a guest post for the Tom’s Planner blog on project planning. Inevitably it turned into a discussion about the merits of product-based planning over other techniques and a debate about top-down planning.
However, what I found engaging and of concern was the idea of planning from the bottom-up vs. top-down planning.
The product breakdown structure (PBS) or work breakdown structure (WBS) have much in common. Both are planning tools that help the project manager determine scope. Both are hierarchical tree diagrams. Both help estimate the effort, time and resources needed to deliver the project.
The correct way―the most complete and accurate way―is to prepare a PBS or WBS from the top. The PBS is derived by decomposing―breaking down―the project into smaller components until the level of detail is enough to accurately describe what is needed to deliver the project.
Why is top-down planning the correct way? Simply because it is logical and results in a full description of what the project needs to produce. Things are less likely to get missed. In How to Write a Project Plan I used a speaker event to illustrate product-based planning. The rational process of decomposing the project into more detail established that promotion was better defined by an advertising campaign and marketing products.
In contrast, the bottom-up approach turns logic on its head. The team attempts to think of all the products (or work) the project must deliver. It’s an unsatisfactory attempt at brainstorming which results in most of the suggestions representing products. The problem with this approach is
- it assumes the requirements are well-defined and understood
- all team members have enough knowledge to name every product and integrate them across all levels
A bottom-up approach is likely to miss products. No, I’ll rephrase this. A bottom-up approach will result in missed products. From my earlier example, would the distinction between marketing and advertising have been understood? Would something be missed? Probably.
It is a lazy way to plan. It is an unreliable way to plan.
What’s more, it often is the advocate of the bottom-up approach who elects to prepare the schedule plan directly from such brainstorming activity. And when they’ve prepared their Gantt chart they say they’re done planning. Poppycock!
There are no short-cuts to effective project planning. Invest your time wisely. Otherwise you’ll get caught out sooner or later.
Have Your Say
Do you advocate top-down planning? Please join the discussion.
Creative Commons image courtesy Kaptain Kobold.