Progress S-curve can be developed from various sources. It can be produced directly project management software such as primavera, MS project, etc. It can also be developed in the excel spreadsheet. How ever, the concept and working procedures are the same no matter which tools are utilized. The two processes called developing and updating are required when working with Progress S-curve. Normally in a project, progress curve is used to measure the project status and report to client as well as internal stakeholders who will take remedial action in the event of project delay occurs.
The following steps should be taken when the progress curve is developed.
- Collect project requirements/scope
- Develop WBS
- Develop baseline schedule
- Assigns planned hours (man-hours and/or equipments hours or budgeted cost) in each activity or each deliverables such as engineering documents and so on
- Calculate the relative weight
- Distribute the percent completion over the time line.
The following steps should be taken when the progress curve is updated.
- Update actual physical progress for each activity or deliverables
- Calculate percent completion
Normally in an EPC project, Engineering, Procurement and Construction Progress Curve and Overall progress curve are produced and used to monitor the project performance. The three WBS element ( Engineering, Procurement and Construction ) are WBS level 1. Overall is a project level WBS called level 0.
Assume that a project scope includes design, procurement and construction of pump station and additonal pipelines for a refinery plant.
Engineering Progress S-curve
According to that project scope, the following documents could be produced for engineering stage.
- Basic Engineering Data
- P&ID drawings
- Line list
- Piping MTO list
- Piping GA drawings
- Pump GA drawings
- Mechanical Seal drawing
- Structure GA drawings
- Pump Foundation drawings
- Electrial drawings
- Instrument drawings
- Construction Requisition and so on
Develop engineering schedule based on the agreed deliverable list. Assign the planned man hour on each activity to be produced engineering documents. Suppose the total man hour to be spent for engineering is 11,500 hrs and the schedule is 6 month. Engineering planned percent complete can be calculated by dividing man hour distribution over time line and total engineering man hour. Man hour distribution would be different according to work load.
Example; man hour distribution over the time line is as follows;50 hrs (in 1st week), 100 hrs (in 2nd week), 150 hrs (in 3rd week) and so on.
Therefore percent complete for 1st week ; 50/11,500= 0.4%
2nd week; 100/11,500=0.9%
3rd week; 150/11,500=1.3%
Final week; 120/11,500=1% and percent complete for total weeks should be 100%. Then, progress s-curve can be produced using charting tool in excel. See creating progress S-curve
When the actual work is started, the actual progress data should be calculated. Update the physical percent complete on each activity/step for each document. Multiply document progress and document weightage. Finally, total percent complete can be calculated by doing sum-up the weightage progress for each document.
Procurement Progress S-curve
The planned procurement progress data can be produced as follows;
- Sum-up the material and equipment cost
- Develop and get the approved baseline procurement schedule
- Distribute the cost over the time line
- Calculate the percent complete by dividing the distributed cost over time line and total material and equipment cost. The distributed cost (planned cost) would be different depending on procurement step and work load. Assume the total cost is 200,000 and schedule is 4 months.
Example; planned cost over the time line is as follows;2,000 (in 1st week), 3,000 (in 2nd week), 5,000(in 3rd week) and so on.
Therefore percent complete for 1st week ; 2,000/200,000 = 1%
2nd week; 3,000/200,000 = 2%
3rd week; 5,000/200,000 = 3%
The accumulated percent complete up to three week is 6 percent. Then the percent complete for total week should be also 100%.
When the actual work is started, update the physical progress on each procurement step for each equipment. Multiply the physical progress of equipment/material and its weightage (equipment cost/total equipments cost) . Finally, total percent complete can be calculated by doing sum-up the weightage progress for each equipment/material.
Construction Progress S-curve
The planned construction progress data can be produced as follows;
Example; planned hour over the time line is as follows;
- Develop and get the approved baseline construction schedule
- Assign the planned man hour on each activity
- Distribute the man hour over the time line
- Calculate the percent complete by dividing the distributed hour over the time line and the total construction hours ( man hour and equipment hour) . The distributed hours would be different depending on work load in a time frame. Assume the total construction hour is 160,000 and schedule is one and half years.
4,000 hrs (in 1st week), 4,500 hrs (in 2nd week), 5,000 hrs (in 3rd week) and so on.
Therefore percent complete for 1st week ; 4,000/160,000 =2.5%
2nd week; 4,500/160,000 =2.8%
3rd week; 5,000/160,000 =3.1%
The accumulated percent complete up to three week is 8.4 percent. Then the percent complete by the end of the project is 100%.
Update the physical construction progress when the actual work is started. Update the actual percent complete on each work step for each activity.Multiply the physical progress of each activity and its weightage (activity hour/total construction hour) . Finally, total percent complete can be calculated by doing sum-up the weightage progress for each activity.
Overall progress S-curve
The overall progress data (planned and actual) can be calculated as follows;
- Calculate Engineering , Procurment and Construction cost
- Calculate relative weightage for Engineering, Procurement and Construction. example; for engineering weightage - total engineering cost/total project cost
- Get engineering weightage progress by multiplying engineering physical progress and engineering weightage
- Get procurement weightage progress by multiplying procurement physical progress and procurement weightage
- Get construction weightage progress by multiplying construction physical progress and construction weightage
- Sum-up all weightage progress (EPC)