Recent discussion http://www.planningplanet.com/forum/forum_post.asp?fid=1&Cat=8&Top=75366 [1] showed that there is a need to explain what is resource workload on certain assignment and why it is not the same as resource assignment quantity.
Workload is usually measured in percent and shows what part of the work time resource is working on activity where it was assigned. The same resource may do in parallel several activities if its total workload does not exceed 100%.
An example: an activity can last 8 hours, assigned resource R has 25% workload, it means that R will work only 2 hours on this activity during the workday. The rest 6 hours may be used on other assignments of resource R. An example; a crane may be busy on several activities during the work day in parallel.
Quantity is always physical quantity of assigned resources (like 4 workers, 3 machines, etc.).
Total resource workload is the quantity multiplied by workload. So 200% may mean 2 resources with 100% workload, or 4 resources with 50% workload. That is why total workload does not give necessary information for resource scheduling.
And unfortunately this total workload is what many other scheduling packages call resource quantity. As the result there is a risk to get wrong information on project resource requirements and create unrealistic project schedules.
Workload is usually measured in percent and shows what part of the work time resource is working on activity where it was assigned. The same resource may do in parallel several activities if its total workload does not exceed 100%.
An example: an activity can last 8 hours, assigned resource R has 25% workload, it means that R will work only 2 hours on this activity during the workday. The rest 6 hours may be used on other assignments of resource R. An example; a crane may be busy on several activities during the work day in parallel.
Quantity is always physical quantity of assigned resources (like 4 workers, 3 machines, etc.).
Total resource workload is the quantity multiplied by workload. So 200% may mean 2 resources with 100% workload, or 4 resources with 50% workload. That is why total workload does not give necessary information for resource scheduling.
And unfortunately this total workload is what many other scheduling packages call resource quantity. As the result there is a risk to get wrong information on project resource requirements and create unrealistic project schedules.