Home › Forums › Microsoft Project Discussion Forum › Relation between Resource Max Units & Resource availability
I have the impression that there is a relation between the Max. Units (Resource sheet) and the time-sliced Resource Availability (units). I have seen changing the Max Units after changing the timeslice Resource Availablity units. However, this is not consistant: especially when a for the future configured resource availability becomes active (because Available From becomes the current day), the Max Units on Resource sheet level does not change.
Does someone can shed some light on how this works?
Max Units (in Resource Sheet) is the availability of that resource on today’s date. This value is calculated from the “Resource Availability” table in Resource Information dialog. It doesn’t consider if the resource is occupied with work or not.
Resource Availability (in Resource Information) indicates the availability of the resource during a particular period. Say 23 Sep 2020 to 23 October 2020 the availability units is 100%. If today’s date is 22 September 2020, Max Units will be 0%. If today’s date is any date between 23 Sep 2020 to 23 October 2020, the Max Units will be 100%.
If I may extend Sai’s comments. There are a lot of inter-twined fields related to units.
Max Units at the Resource Sheet serves as the default Assignment Units when that resource is initially assigned to a task. If Bob’ Max Units is 80% and Bob is assigned to Task A, by default, Bob’s Task Assignment Units will be auto-filled-in at 80%. However, once the Assignment Units are defined, any changes to Bob’s Max Units will NOT alter any task with Bob’s Assignment Units already defined on that task. Meaning, if I changed Bob’s Max Units to 50%, Task A will still show Bob’s Assignment Units at 80%.
When the schedule is Resource Leveled, Task Assignment Units drive the majority of the leveling process and the Resource Sheet Max Units are used to check for and flag over allocations.
So if you look at the big picture;
* Resource Availability (Resource Information) defines availability over an extended (typically) period like a year. These are also used to define changes in billing rates (On May 10th, Bob’s project cost increases from $40/hour to $50/hour) if the project is tracking costs in this manner.
* Project then Resource, then Task Calendars define which days the resource is working and for how long on each day. Project calendars typically define project work days. Resource Calendars define work/vacation days for a specific resource. For example, Bob works the normal 8 hour days from the Project Calendar except next Wednesday when he only will work 4 hours total. Task Calendars override the other calendars for that specific task only. For example, Bob’s typical work week is M-F, but for the implementation task, all assigned resources will work on Sat/Sun.
* Max Units (Resource Sheet) provides the default Task Assignment Units when the resource is initially assigned to a task and are used for over allocation detection during Resource Leveling
* Assignment Units (Task), defines the percentage of time that the resource can work on that task on any work day as defined by the Project/Resource/Task Calendars. Note that the Assignment Units is the percentage of total work time available based on the Calendars. If Bob is assigned 50% on Task A, he would be scheduled 4 hours/day for his normal 8 hour work day. If however, Bob was only available to work a total of 4 hours on Wednesday, then the 50% is based on the total availability of 4 hours.
Hope this helps
Thanks Sai & Daryl for these clarifications.
Sai said “This value is calculated from the “Resource Availability” table in Resource Information dialog.” ==> I have done a quick test and I have not seen the expected result:
On 24/09 I’ve created a new ms poject file with 1 resource Tonia with following availability:
From: not defined to: 25/09/2020 100%
From: 26/092020 to: not defined 75%
As expected, when I look at the MAX-UNITS in the resource sheet today, 24/09/2020, I see 100%. Which is correct.
When I now change my system date to 26/09/2020 and open the ms project file, I would expect to see the MAX-UNITS to be 75%. This is not the case, the MAX-UNITS remains 100%
I do have a screenshot of this which I could share but there is no way to add pictures, files in this forum.
Hi Koen, This should work. After changing the system date and opening Project, check Current Date in Project > Project Information. Max Units knows today’s date from Current Date field.
Sai, I’ve just checked the Project Current date in Project information. This is set to 26/09 (same as system date). However, the MAX-UNITS is not in line with the % from the Resource Availability table. How can I share some screenshots here?