Problem definition
Determine why a WBS oriented by element of cost or
organisational element cause problems when used for earned value management
Feasible alternatives
WBS with cost element orientation
WBS with organisational orientation
WBS with product-oriented
Develop the outcome
of each alternative
Fig. 1 Cost Oriented
WBS
Fig. 3 Organisation
oriented WBS
Selection of criteria
Ease of assessment of progress status
Ease of communication
Bases for historical data
Analysis of
alternatives
Consider figs 1,.2 and 3 above,
With the product oriented approach of fig 2, the logical
level 2 WBS elements were Skid, Pipe spools and paint. Questions on status of
the project are easily explained by the status of the skid, the spools and
paint. A glance on the report shows where the project is.
The cost oriented WBS shown in fig.1, the status of the
skid, pipie spools and paint is fragmented into multiple control accounts of
equipment, materials, labour, indirect and administrative. Obtaining the status
for the skid for instance entails collecting data from all the cost legs and
summing up. This becomes cumbersome where you have multiple key elements of the
project.
The organisational oriented approach of fig. 3 contains some
redundant information. The 2 main element in the project skid and pipe spools
cannot be easily assessed as this is not the function of OBS. Using OBS in WBS
negates the value purpose as information are duplicated.
Selection of
preferred alternative
Earned Value Measurement is a project control tool that
focuses on earned value of work performed as project progresses and allows for effective
measurement of the status in terms of both cost and schedule. In the three scenarios
in figs. 1 to 3 it is clear that only fig.2 gives a visible status of the project
in terms of the 2 main level 2 elements- skid and pipe spool fabrications. Therefore
product oriented WBS is unambiguous project control tool in earned value measurement.
Performance
monitoring and evaluation
With the product oriented WBS, the 2 main level elements of
the project can be taken down to level 3 comprising handrails, skid frame, pipe
supports and pipe spools 1, 2, 3, etc and progress tracked both in terms of
schedule and cost.
References
Humphreys, G. C. (2011). Project
Management Using Earned Value, Project Management Using Earned Value (2nd ed.), (PP. 31-42) CA, Humphreys &
Associates, Inc.
Humphreys, G. C. (2011). Definition of Scope, Work Breakdown Structure
(WBS) and WBS Dictionary, Project
Management Using Earned Value (2nd
ed.), (PP. 45-58) CA, Humphreys & Associates, Inc.
Humphreys, G. C. (2011). Relating
Organisations, Responsibility, and Work Scope, Project Management Using
Earned Value (2nd ed.), (PP. 91-100)
CA, Humphreys & Associates, Inc.
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