Max Units and Duration

[SymC1]

I'm in the process of setting levels of productivity for staff so that they have time to manage ad-hoc tasks around assigned project work.

For example: Graham is available for project work 50% of the time. I've set max units to 50%.

When I set up a task in the gantt chart I specify its duraction e.g. 7 hours. When I assign Graham to this task I'd expect it to spread it accross two days so taht graham effectively works 3.5 hours per day. What's actually happening is that Graham is assigned to complete the task in one day but only has 3.5 hours to do it, as if he needs 50% of the time normally required.

I changed Graham's max units to 90% and likewise it expects him to do a 7 hour task in 6.3 hours, rather than spreading it over parts of two days.

I'm obviously setting this up incorrectly but what I woudl like to achieve is as follows:
I set up all resources with there productivity percentages;
I enter the actual duration of each task in hours;
Project adjusts the durantion to suit the assigned resources availability, but still shows me how many hours I've planned originally (i.e. if its takes someone 14hours to do a task on 50% productivity - I still need to see it's 7 hours of effort).

I'd really appreciate some advice on how to get this working correctly.

Thanks

 

[SymC1]

I think I've resolved this issue by changing from Fixed Units to Fixed Work as the task type. I now have another problem.

I'm seeting up a workshop which I expect to take 10.5 hours (1.5 days) of effort.

I expect the duration to be 3.5 hours (0.5 days)

I want Stephen to attend who has max units of 50%; I want Shaun to attend who has max units of 75% and I will attend and have max units of 100%. As this task doesn't conflict with any other I'd like to simply book each person for 3.5 hours but project tries spread the time across the resources, each spendinga different amount of time in teh workshop.