Despite a relatively long history and plenty of literature on the subject, project management keeps failing to consistently deliver on time and within costs. The usual suspects for these failures are called uncertainties, that ever growing safety margins are unable to absorb.
>Lisez moi en français : Performance en mode projet et oubli de tâches
Surprisingly, a closer look to the reasons to miss the due dates shows that variability and uncertainties are in the Pareto’s tail with the trivial few, while forgotten or unforeseen tasks are the main causes of delays. Explanations.
The Pareto diagram or analysis I refer to is the one built upon the analysis of buffer consumption in Critical Chain Project Management (CCPM). In a nutshell, CCPM differs from classic Critical Path Method (CPM) by replacing the individual safety margins supposed to protect each task from slippage by a unique and shared project buffer. This one acts like a shock absorber protecting the promised project delivery due date.
In order to build this buffer, the individual margins are mutualized. Using the same principle as insurance contracts, based on the low probability of cumulative odds, the buffer size (in time units) can be significantly reduced compared to the sum of individual margins. The latter having consistently failed to protect the projects from slippage, despite their inflation over time.
Every task exceeding the initially estimated duration is consuming the protective buffer without jeopardizing the project itself. CCPM also encourage behavioral change, like turning in deliverables or handing over as soon as the job is completed. If the duration to complete the task is shorter than estimated, the project buffer is extended accordingly. The CCPM protective project buffer can therefore also be seen as an inflatable safety device, “breathing” as the project goes on.
In order to improve project execution and reduce the future projects overall durations, the CCPM project buffer consumption is analysed, hence the mentioned Pareto diagram.
One may be surprised to read that unscheduled and forgotten tasks are among if not the main reason for project slippage. How can that be?
One understandable reason is novelty. The project team is working on something totally new, never made before and is not fully aware of what is required to achieve the project. This is only half legit though, as risk assessment and/or a thorough necessity-based analysis ahead of time would reveal most of the missing tasks, if not all.
Alas, risk management is seldom correctly done and necessity-based analysis ignored. Instead of a rational analysis, many teams rely on brainstorming to list the jobs to be done in a project. Doing this is ignoring the fundamental difference between creativity techniques and necessity-based logical analysis, most likely ending with lots of tasks that are nice-to-have rather than truly required prerequisites.
Another reason for forgetting tasks in the Work Breakdown Structure (WBS) is the lack of rigor in planning. Fancy PowerPoint decks or Excel sheets are often preferred to Network Diagrams and Gantt charts. Willingly or not, this is an easy way to confuse the attendants of a project review and leave missing tasks unnoticed.
New planners, newbies, a junior team member or even a seasoned newcomer may not have enough knowledge about the local practices and forget some tasks in their plannings. This is often the case if templates haven’t been developed as standards.
Patching the holes
When missing mandatory tasks are discovered, there is no way but to patch the holes and insert them into the planning, with all consequences regarding project duration. With some luck, the patch is not on the critical path / chain and will not impair the project deadline.
Now one cannot count on luck to be successful and Murphy’s law got it’s fame ruining many hopes that everything is under control. Chances are that the patch(es) will adversely affect the overall project duration and lead to a slippage of the deadline. Unless the project is managed the CCPM way and the project buffer is sufficient to absorb the unplanned activities AND still protect the deadline against other unexpected events. If those conditions are not met, rescheduling is mandatory.
Note that one way frequently used to cope with this kind of problems is to stick to the initial commitment of deadline and downsize the project. This can be done by suppressing features, reducing some options, downgrade some specs. Customers may be forced to accept this unilateral revision of specs for keeping the deadline.
How to prevent forgetting tasks?
As mentioned before, a rational necessity-based logic analysis of all prerequisites to achieve the Goal (deliver the project) is a good way to (almost) exhaustively list all necessary tasks, steps and milestones.
Build a Goal Tree
The tool to run such an analysis is called the Goal Tree. Among the many benefits of using a Goal Tree ahead of scheduling is the fact the Goal Tree in itself is a WBS. Therefore this tools enhances the exhaustive listing of the jobs to de done but saves time as it provides a pretty good base of WBS as well.
> Learn more about the Goal Tree
The Goal Tree is advised for new projects or when templates do not yet exist. When templates exist and are relevant for a new project, they should be used. They provide guidelines and are a kind of knowledge base. Templates should be developed and used like standards.
Templates are not supposed to be one-size-fit-all solution, but should be tailored for suiting the purpose. Usually one template is used per project type or product family, etc.
Templates should evolve over time in order to embed lessons learned, improvements, etc. yet without growing into a unmanageable collection.
Many people confuse brainstorming with setting ideas in order. Brainstorming is a creativity tool and should be used as such. Structuring a project is not a creative activity, therefore brainstorming is not the suitable tool for listing all necessary tasks.
Not only does brainstorming not give enough guarantee that all required tasks will be listed, brainstorming is an invitation to add nice-to-haves which are not necessary – as their name tells – nor even relevant.