Align or Decline: Why Matching CBS and WBS Is Critical for Project Success

Does your cost breakdown structure match your work breakdown structure in your project?

In a lot of projects, both do not always match and the following are some reasons why:

1. Planners/Schedulers are often mobilised later on a project. Most times at the project start, high-level schedules with few lines are usually enough for stakeholders
2. Cost is always deemed more important than Schedule. Repeating what I said in number 1, most times at the project start, high-level schedules with few lines are usually enough for stakeholders but cost estimation attempts to be as detailed as possible even from conception. We tend to forget that time is money.
3. Where the planning/scheduling team is mobilised early, the different project teams including scheduling and cost teams begin working independently/ in silos caused by:

• the need to meet up to complete the overall project planning as fast as possible. Planning here means developing plans including scheduling, cost budget, quality plans, etc.
• Lack of team synergy and integration.

4. For most contractors, the cost model and CBS are handed over to them by the client in the contracts in the form of payment structures: that is what the contractors tend to mirror.

Challenges the Mismatch will cause:

1. Cost loading of detailed schedules becomes difficult.
2. Overall/Integrated project monitoring and controls become challenging: costs are skewed away from the schedule.
3. Of course, performing EVM becomes tough with unrealistic results.
4. Performing integrated schedule cost risk analysis becomes challenging. Though most QRA software like Deltek Acumen, Safran, etc. try to make it easy to map your costs from whatever format and arrangement it is to your schedule but it is not usually effective. Here is my experience, a lump sum cost estimate consists of estimates for 2 different activities with two different WBS but the lump sum was not broken down in the original estimate document/software. The solution can be to tell the estimator to break it down but there are thousands of them and unseparated actuals have been implemented on them.
5. Most importantly, when delays, extension of time and need for recovery, it becomes hard to align and realign the project.
6. One I have personally experienced, it becomes difficult to synchronize your cost and schedule on your project management tools. I wanted to synchronize approved cost on SAP with the baseline schedule on Primavera P6 and it was nearly impossible.
7. The out of sync between WBS and CBS can even affect your Integrated reporting whether Excel or Power BI. Each one's values and charts will be speaking out of tune with the other on the dashboards

So, no matter how you think it is unnecessary to align the CBS and the WBS, at the project start, everything will appear fine. But down the road for the project, it can become messy.

Just like Primavera P6's schedule, everything looks fine on the schedule at the beginning but when you start updating, the schedule may start looking strange due to all your own chosen default settings and set-up.

Therefore, let your schedule meet your cost closely by matching your WBS with your CBS as early as possible. Both should have similar nomenclature or names and ID/numbering, it will pay you down the road!

Overall, all your project plans: schedule, cost, risk, quality, procurement/supply chain, HSE etc. must match and be integrated together for a seamless project success.

What do you think?

What challenges have you faced not matching CBS with WBS?

Have you resolved such challenges before?

Share with us here!