Project Weightage Distribution

Hi Guys,

This topic is something very much interesting to me.

Hence i would like to go little detail about this.



In my last employment, I was working on client side. My company was putting new plants based on the market demands & R&D output.



SO , in all our trackers we used to use cost as the weightage factor.

We pay consultants (Technip..etc) for engineering, procurement done by us, construction by contractor , commissioning and start up by us.



But things were different when I joined contractor. Here we put weighting to construction activities based on manhour.

We use ’Top down’ weighting system.

List manjor WBS elements first:

1)ENGINEERING

2)PROCUREMENT

3)QULAITY

4)PLANNING

5)HSE

6)CONSTRUCTION

6.1)ONSHORE FABRICATION

6.1.1)STRUCTURAL

6.1.2)PIPING

6.1.3)E&I

6.2)OFFSHORE INSTALLATION

6.2.1)STRUCTURAL

6.2.2)PIPING

6.2.3)E&I

7)COMMISSIONING (client)

8)DOCUMENTATION



Now assignment of top level % is purely based on expert judgement.

Our involvement is mainly in fabrication & installation.

(70% of material issued by client, engineering by consultant)



So lets give 90% for off-shore fabrication and installation

Distrubute the balance 10% for other headings (Planning, our minor engg involment. quality, planning & hse)

This distribution is again based on ’quantum of work ’ or ’importance’.



Now the 90% can be distributed between onshore & off-shore based on the target / estimated manhours.



Say we have 1 Mn manhours for on shore fab & 1.5 Mn mhrs for offshore.



Then weighting for 6.1)ONSHORE FABRICATION is:

90 % X 1/(1+1.5)



Then weighting for 6.2)OFFSHORE INSTALLATION is:

90 % X 1.5/(1+1.5)



For all sub activities under the heading 6 , we may apply the weighting based on mhrs.



What is best indicator for weighting : manhours or duration ?

Its again manhours for me.

(Duration can be reduced using crashing , but the manhour required to perform an activity is more over the same)



I am planning to share my ’Progress tracker’ application with screen shots , in the form of a step by step tutorial in my PM blog ’PM Karma (http://pmkarma.blogspot.com/) ’ soon.



Anyway , its great exchanging our ideas. PP rocks !



Cheers



Sreejith Nair

http://pmkarma.blogspot.com/

Hi Charlie,



Better to read your post here and not in the “Working in the UAE as a Senior Planner / Manager “.



Could you explain a bit your statement “Each activities will be assigned percent weight equal to activity duration/sum of activities durations”.



Weighted values for activities depends of the project phase. For instance:



Engineering phase: weighted values based on man-hours per deliverable. Roll up by activity and by discipline.



Procurement phase: weighted values based on one or two parameters. Mandatory parameter is cost, optional parameter would be delivery duration.



Construction phase: weighted value based on man-hours. Sometimes you can see weights based on cost. I do not recommend cost due to the cost structure for construction activity.

Normal cost structure has 3 components: labor, consumable materials and equipment. Some activities with high cost is due to consumable materials or equipment but no labor . Based on this, cost being used as weight is not a reliable parameter of activities.



Weight based on duration for Engineering activities is giving us wrong information. Some activities in Engineering have long duration with manhours budget very small. What is best indicator for weighting : manhours or duration ??? for me manhours.



Cheers,

Hello Abd Aziz,



The fundamental in weight distribution it to arrive at common matrix, cost, manhours, etc. A simple case is the duration of each activities as common matrix.



Each activities will be assign percent weight equal to activity duration/sum of all activities duration.



In P3 it is very easy to do this by assigning a resource WP for each activity, use export-import to load the value WP for each activity or use global change.



As you identify the activties within the WBS at whatever level, all you have to do is to summarize the WBS, you will get the assign weight distribution of that WBS at whatever level.

Hi Abd Aziz,



Wt Distribution is always depending on what report are you going to generate.



Example:

1. If you are working on the spreadsheet and dealing a work items with estimated qty and unit cost, then therefore you can easily calculated the wt for each item as against the overall cost.

2. If you are dealing a work items with estimated manhour then you can also calculate the wt using manhour.

3. In P3, I used to load these information (Resource Loading) both qty and unit cost and sometime the manhour...but having hardtime to present the wt percentage in the graphical presentation (bar chart - column format)...so I always end up preparing it in spreadsheet format...



Hope this input will help...



Ronald

PMI’s Construction Extension (to the PMBOK Guide Third Edition) Second Edition 2007 item 6.7.2 Activity Weights Definition : Tools and Techniques under Expert Judgement states that "Specialists can determine which activity attribute should be used for determining activity weights for each level of the WBS. In the first levels of the WBS, the attribute is USUALLY the deliverable COST."

Hi



PMBOK not necessary tell you how to build a spaceship, however, it teaches you how to manage the project in order to finish the spaceship on time and on budget.



The weight distribution for each project is different. and in accordance with the contract terms and condition. you have option to use man hr, quantity of materials m3, cost, unit output ... the list just go on .



Al

In my experience on design engineering project, we use a ration of the WBS hours to the total manhours of the project.



Cheers,



Kunle