Most project management frameworks and methods advocate (and actually require) ’point-estimates’ in planning and scheduling. By ‘point-estimates’, I mean there is a ‘hard number’ that seems to be etched in stone, leaving with no ‘tolerance’ or ’leeway’ for the project manager and his team. Even though we all understand that estimates are never point-estimates (and hence the project commitments are never a point-commitment), we still expect a firm estimate (and consequently a firm commitment) from a project manager.
For example, a given feature must be required by 23-June, but there is no recognition of the fact that 23-June might still be a couple of months away, and several things could go wrong or could change meanwhile thus affecting the validity of this date. In real-life, there are always tolerances, some allowable, some acceptable, some tolerable and some simply unacceptable. This is not limited to schedule along, but also apply to cost, quality, scope, project benefits, etc. In some cases, the tolerances are defined, for example for the project scope, requirements might be prioritized as ‘M-S-C’ (or Most, Should and Could). In a previous organization I worked for, we had a great system for prioritizing all product requirements as ‘A’ (for current version), ‘B’ (implement if time is available) or ‘C’ (long-term requirement, but is being identified right now just so that designers and developers are available of how the system will evolve over time - so that, hopefully, they could build their designs futureproof). However, most product managers are unwilling to commit to such tolerances (or atleast unwilling to acknowledge existance of such scope tolarances), perhaps fearing that development team will straighaway prune down the list to bare minimum ones. Hence, in most organizations and projects, there seem to be two sets of commitments: one set is for the customer and one set is for the team. The one for team are the more stringent ones, but in the heart of the hearts, upper management knows that not all of them will be achievable and hence makes a little less stringent commitment (perhaps a more realistic one !) to the customer, thereby cushioning themselves against Murphy and the real-world. The project team slogs over months, often spending long nights and weekends alone in office just to try and meet the set of commitments that have been given to them, hardly ever realizing that there is another set of more realistic commitments that perhaps don’t acknowledge the cost of their commitment and efforts the team members are currently paying.
Agile methods, and Scrum in particular, take a major step forward and acknowledge that long-term plans are prone to later-day variations (and thus a waste of time and effort for all practical purposes) and hence favor short iterations to minimize the possibility of a project drifting or overcommiting itself to impossible deadlines due to such wild and optimistic estimates for long-range plans. But, it goes a little too far by simply accepting a world where no project tolerances are recognized, let alone identified for a project or its iterations. When a team member comes back and informs that he needs more time to complete a task than originally estimated, it simply makes suitable changes in the sprint burndown chart without placing an upper-boundary condition on how much off-estimation is permissible? As per the revised commitments, if the engineer is able to complete the task in the current sprint, well and good, but if for some reason, he is not able to complete, you simply push it out to the next sprint. It may not be necessarily bad, but definitely doesn’t place any upper-bound on the allowances available to a project team, and hence might not find good favor from upper management or product management in the long run.
PRINCE2 not only legitimizes the existance of tolerances at project level, it also allows a project to inherit a portion of those tolerances at stage plans and team plans at various stages thus giving a reasonable and mutually-agreed upon leeway to project manager and team managers to use those tolerances to manage the projects better (than, say, worrying about some 2-day delay that they can’t avoid or not able to meet a scope requirement because some peripheral feature can’t be met in given time). The mere act of legitimizing project tolerances creates a healthy understanding among all stakeholders that in real-world, there will be variations in future due to factors that might not be known or understood fully, or might simply change over time. A prudent project manager might not restrict himself to his current project management framework, and might want to look at what PRINCE2 has to offer in this regard.
How do you handle project tolerances ?
