Frank Patrick made an excellent point on the misconception of resource utilization on his blog a few days ago that I somehow missed! (Thanks, Frank, for pointing this out)
Im glad Im not the only one that sees organizations striving to over-allocate their resources! The worst part of this kind of overallocation is that it is disguised as perfect allocation. Applications like Microsoft Project ask you to define the threshold it will use to determine if a resource is "overallocated". In Project this is called the "Max Units" field. Then you assign resources at a given Units value and if Project sees that for any given time period the sum of the assignment units for a given resource is greater than their Max Units value that resource is seen as "overallocated". So the sticky part is where to set Max Units. 100% is the default out of the box and there are organizations that think that is a goal. It makes sense when you first think about it. "I want my resource to be fully allocated." Well sure. Who would not want that! But if you have someone assigned to even a single project (because you have recognized the evil that is multi-tasking) at 100% then they are not OVER allocated on paper. But they really are because NOBODY is available 100% of their X-hour work day. They answer email, go to meetings, get asked questions by coworkers and sometimes they even get up to go to the bathroom!
Most 'authorities' agree that the real amount of availability for a resource is somewhere between 65% and 80%. Im kind of in the middle of these two figures at about 70%. That gives a resource about 2.5 hours a day to "other things". This also acts as a buffer so that if a resource does have to push it and work more than that 70% they are not automatically in OT territory.
So if you are using Microsoft Project to manage your schedules/resource usage then make a note to examine the Max Units values for your resources. If they are at 100% you may want to rethink it to take these concepts into account.
Don't have time for a fully thought-out response, but...
Good points, Brian, but all those percentages are a pain. Keep it simple. Instead of worrying about 65% or 70% or whatever, why not just estimate in terms of days, in which personal availability levels are assumed to be part of the mix? And instead of agonizing over where to set "max units," why not just swag the amount of historical time resources are doing non-project work and simply limit the available resources to such a number? Of you've got 10 people carrying a particular skill and they spend 30% of their time on maintenance and day-to-day stuff, just put in 7 people against which projects can be promised. (Maybe this is the same thing as Max units, although I'm not talking about names for resources, just bodies that carry the skill.) And finally, rather than worrying about the percentage of time people don't spend on a project task, design, support, enable, and enforce workplace behaviors that encourage them to work on tasks with single focus. (Oh, and use a critical chain plug-in for MSP to provide rational resource leveling BEFORE determination of the critical path/chain.)
Posted by: Frank Patrick | Monday, March 08, 2004 at 04:46 AM