Work Package in Construction Industry
There are many ways to describe work package. According to Wikipedia (as of October 10, 2012), work package is a subset of a project that can be assigned to a specific part for execution. The keyword here is specific. In construction business work breakdown structure, this is translated to level 3 or 4 job execution.
Why work package?
In the construction business, “Where are we now? How far are we from completion? How many percent complete is this project?” are common questions typically asked by construction manager or project director. In a project of 10 million man hours, those questions are not easy ones.
The logical response to that challenge is to create a divide and conquer approach. A big project is divided into sub project / job codes, job codes divided into activity codes, and finally activity codes into work packages. Division can be by discipline (structural, piping, mechanical, electric), nature of job type (fabrication, construction, material handling), or simply follows modular engineering design.
ACME fabrication yard is constructing a pipe rack module deck.
Step #1: Identify the construction sequence
#1: Fabricating piece mark (individual part)
Job description: cut stiffeners, cut primary beam, cut secondary beam
End product: stiffeners, beams
#2: Assembling piece marks
Job description: Fabricate frame components
End product: beams with stiffeners welded
#3: Site Assembly
Job description: Site installation (install frame components on site)
End product: deck frame installed
Step #2: Assign (estimate) man hour into each work package
To establish work package’s function as progress tracking, planner must put weight into each work package. This is where the dilemma lies. Exact calculation of man hour allocation as per fabrication drawing requires extensive resources, while careless estimation may give false representation of the actual. Generally, approach that fit somewhere in between those two options are chosen. Package to package tonnage comparison approach can be utilized.
The breakdown of activity codes M07_B99 (Fabrication and installation of module 7 deck structure) into work packages may look like this:
|Work Package No||Work Package Description||Man Hour|
|M07_B99_002||Cut Primary Beam||MH2|
|M07_B99_003||Cut Secondary Beam||MH3|
|M07_B99_101||Fabricate Deck Frame Component||MH4|
|M07_B99_201||M07 Site Installation||MH5|
Step #3: Execute work package, update status, and roll up progress
Once the numbers (MH1 – MH5) defined, shop / production engineer can start to update the work package status as per actual progress. For example work package M07_B99_001 (Cut Primary Beam) progress status may looks like this:
|Piece mark||Cut (50%)||Grind (40%)||QC inspection (10%)|
Assuming that each beam has same amount of man hour allocation, this work package is 56.7% complete.
(4 X 0.5 + 3 X 0.4 + 2 X 0.1) / 6 = 56.7 %
Consequently, contribution of this work package to job code M07_B99 is
(MH2 / ΣMH) X 56.7%
This job code progress will then be rolled up to subsequent higher level up to project code.
- Work package should be planned in such a way that can be closed in few weeks. Do not leave it open for months otherwise it will require extra time to maintain and become unmanageable.
- Work package arrangement is always depends to yard resources. Jobs of the same types are not necessarily to be done in the same work package. In certain situation, it may be beneficial to share the load into two shops (two work packages).
- There is no fix guideline on how the yard planners must arrange the work package register. My recommendation is: yard planner must fit their arrangement to their 3 – 4 weeks foreseeable future. In cases with material availability problem, same job can be delivered into two work packages.
What pipe rack looks like: