Project Planning

Hello

Based on three tables (Projects, Tasks and UserCalender) I would like
to work out the total amount of available resources (UserCalender
table contains a entry for each user for each day, day being 7.5
hours) and total required effort (sum of Tasks.EstimateLikley) split
over 12 months.

For example:


Jan:
Available Resources: (4 Users, 7.5 hours per day, 5 working days per
week, 23 Working days in Jan) = (23 x 4) = (92 * 7.5) = 690 Available
Hours
Required Resources:
Project Start Date: 1/1/2007
Project End Date: 1/6/2007
Total Required effort (Sum of Tasks.Hours for above project): 500
Hours Average over 6 months = 83.33 Hours per month, so in Jan I need
to deduct 83.33 from 600 = 516.67 Hours.

etc

How could I do this, I have tried several ways but finding it hard.

Thanks