15.4.15

Why a Critical Approach in Project Management?






"Critical path, Critical Chain, Critical time for completion, Critical thinking, Critical slacking, Critical methods, ..." All these critical words aim to identify and underscore the projects backbone or the minimum set of vital activities for Project Management, not only in terms of time and durations, or linking tasks with predecessors and successors but also in terms of constraints level, manpower mobilization and other settings such as complexity index proper to each work package or deliverables followed by Control Project Teams.

In fact, the "Criticality approach" in Project Management reflects the real obsession to control and monitor the work to be performed, since mid of the 1950's, when first Critical Path was issued by BOOZ ALLEN HAMILTON firm. But Models and schedules, since that time, become more complex with the integration of new settings to optimize workflow and productivity. 

Why a Critical Path?

Something critical could be defined as crucial for the Management in Time. The Latin roots of this word (criticus) suggest that the criticality approach is linked to “crisis” and “solving the faced problems”. As Time dimension is a goal for finishing a project, the critical path becomes a sort of compass to direct the work. It helps to make a decision regarding a technical context and the scope of work to be performed.
In Project Management, a Critical Path is the sequence of project network activities which add up to the longest overall duration. This determines the shortest time possible to complete the project. Any delay of an activity on the Critical Path directly impacts the planned project completion date.
Algorithm of Critical Path is a pure Mathematical approach based upon:

-       An identified WBS including all activities to be performed within a Project
-       Duration tasks (Start / Finish)
-       Dependencies linking (Predecessors / Successors)
-       Logical End Points (Milestones / Deliverables items / Key Meetings for GO- NO GO)

The Algorithm looks like a 4-D plot, gathering 4 levels of information. Otherwise, the Critical Path is influenced by time for completion (durations) and a logical network links. But if you add “allocated resources”, you get the Critical Chain Approach. A resource-leveled schedule may include delays due to resource bottlenecks, because some of them are unavailable at the required time, they impact Project completion date.
Definitely, the reliability of the Critical approach in Project Management is a proof. Software like Primavera, Ms Project … was inspired by this Algorithm to ease calculation for time completion. The Critical Path Method is well-known, wide-shared and completely deep-rooted.

KPI(s) of Criticality?

In case of a first Baseline Schedule, analysis must highlight indicators which proceed to show off feasibility of the Project and help Managers making decisions.

After identification of the Critical Path – stage zero, here are some major indicators:
  1. Critical Time for Completion which means literally the Duration of the Longest Path. It aims to determinate the Target Date for finishing.
  2. Volumes of Critical activities : Number of Critical Activities regarding the entire Work to be performed : (example : PRIMAVERA gives this information in the SchedLog.txt)
  3. Percentage of Critical Activities (PCA): % = Critical Workload (Hours) / Total Workload Project (Hours). This indicator could be reached with an S-Curve using a filter “critical”.If % of PCA < 50% or > 80%, accuracy of the schedule is not reliable.

  1. Critical Density: This indicator focus on the period when the S-Curve of Critical Workload is increasing fast. Very close to strategy for project execution.
  2. Critical Resources or bottlenecks: Applicable to the multi-project Management, being unavailable at the required time is a risk for delaying a Project. This indicator is proper to the Critical Chain Method when allocation of resources is fixed and controlled.

No comments:

Post a Comment