Primavera Resource Loading
Most construction schedules in the United States are not resource loaded, meaning that cost data and/or hours have not been assigned to the activities. When cost data is provided, it is often utilized for payment purposes or to develop cash flow projections. The owner has a vested interest in knowing in advance how much money the contractor might expect to be paid each month if the project goes according to plan. Beyond this, having cost data in the construction schedule does not create many advantages for the contractor. Cost-loaded schedules have a tendency to be viewed as payment tools wherein progress is constantly disputed by the owner and the contractor finds it very difficult to update the schedule without interference.
Resource loading is an entirely different matter. There are techniques for restricting the amount of work being performed by any particular trade that are understood by seasoned schedulers that can avoid the additional step of assigning labor hours (not to mention, equipment) to each activity.
Even when these techniques are not employed the problem is generally not that the baseline CPM schedule is unrealistic but that slippage to non-critical activities once the project has started changes the dynamics of the expected labor.
Resources are always finite, meaning there is always a practical limit to how many workers are available in a given time period and can be utilized effectively within the confines of the project site. If the schedule is not “tight” the delta between early and late dates in the schedule creates a wide range of possible dates on which any particular task might be performed. Activities slip and begin to overlap with work that initially (in the baseline CPM schedule) would have started much later. While it is true that critical path activities can also slip, it is the secondary (non-critical) tasks that often slip more and are ignored as a result of the available float.
Construction Science noted the problem with schedules that assume unlimited resources many years ago and developed techniques for dealing with this very significant issue. Putting resources into the schedule is certainly a very good idea, but in our experience there are other methods that are also very effective. We primarily utilize resource loading to help our subcontractor clients understand how updates to the master schedule is impacting their work. Comparing resource curves from one update to the next is the best way to summarize how the master schedule has changed.
Click here for additional information or pricing.
var _gaq = _gaq || ; _gaq.push(['_setAccount', 'UA-19273555-1']); _gaq.push(['_trackPageview']);