The author realized that EVM analysis became difficult when there is a scope change, rate escalation, or in projects where the output is not discrete but exclusively based on level of effort. Other practical issues faced during EVM implementation are tracking costs at lower level, especially when task completion is measured using a binary system. A project governance system which is silent on cost collection system, EVM related project team roles and responsibilities, and data sharing is sure to upset the EVM analyst’s effort in forecasting the future outcome. Also of significant consequence, is the inaccuracy of the plans, the mismatch between progress and corresponding work elements as per plan and nonintegration of the plan with the WBS to enable tracking of the budgeted cost values. Above all, EVM analysis fails to yield fruitful results while analyzing cost and time over-runs
Paper EVM can be marketed as a wonderful project management tool only after few of its inherent weaknesses are addressed. This is what I term as “fool-proofing EVM”. Possible on EVM Before the drawbacks, it is important to list them down asimpact well as trace their sources. S. addressing No. Drawbacks Source of drawback analysis result 1
Cannot track effectively if scope/ cost parameters change
If they are altered to accommodate the change, then it might become difficult to reflect the original delay.
PV, EV and AC values depend on the baseline cost / schedule / scope parameters.
2
Difficulty in tracking costs at lower levels, especially when progress is measured in 0/100 system and not incrementally.
Inaccurate capturing of EVM metrics and thus, inaccurate reporting.
Cost calculations for intermediate stages of progress are difficult.
3
Lack of information on progress or cost budget.
Inability to generate reports on time.
Poor project governance
4
Plan related – Inaccuracy of baseline plan or non-congruency between planned and actual work under progress
Inaccurate inferences being drawn.
Miscommunication / Quality control failure resulting in mismatch between underlying data elements between PV and EV.
5
Inability to report schedule progress towards project end
Inaccurate reports that cause confusion to the uninitiated reader.
Design of EVM analysis
In cases where there is a scope revision, the EVM analyst must freeze his analysis on the progress until the revision date and make a note of the reasons for variance, if any. The date until which the old baseline was valid and on which the analysis was frozen shall be called the cut-off date. Then, post re-baseline efforts, the analyst must create a new PV / EV/ AC chart but start plotting PV curve at 0 duration from that point on Y-axis, which represents the PV of the cut-off date. The revised planned value curve may be plotted from that point. Similarly, EV / AC also must be plotted on Y-axis on 0-date and the progress may be tracked from that point, instead of the origin. 14