Ms project 2010 - grouping how to show the duration between dates at the summary level

Question

Hi we have a ms project plan where we have used grouping to present the task breakdown in a different structure.
This works great we get at the summary level the start and finish dates correctly but the duration gives us only the Maximum value for the durations of the tasks within the group. (is it possible to change the maximum calculation?)
We would like to be able to determine the duration at the summary level. Of note if we use functions such as projdatediff(start,finish) this only gives the result at the detail level and does not show at the summary level - even if we check the do the
calculation for the task and group levels 'use formula' radio button.
is this a bug???.
If we use a numeric calculation such as finish-start we get a figure that allows  us to repeat the calculation at the group (summary) level. but firstly we do not actualy know what the numeric value represents. i.e (Finish-Start)*10000 for
a duration of 0.5 hours = 208.33 ,1 hr= 416.67,1.5 hrs =625, but 8 hrs is giving 10833.33 which is 24 * the 1 hour figure
duration  finish-start  start           finish
0.5hrs     208.33    Tue 31/01/12 Tue 31/01/12
1d          10833.33 Tue 31/01/12 Wed 01/02/12
8 hrs      10833.33 Tue 31/01/12 Wed 01/02/12
0.19d     625          Wed 01/02/12 Wed 01/02/12
1.5 hrs   625          Wed 01/02/12 Wed 01/02/12
0.13d     416.67     Wed 01/02/12 Wed 01/02/12
1 hr        416.67     Wed 01/02/12 Wed 01/02/12
Anyhow looking for suggestions on how to get a calculation of the difference in two dates as units (pref days) into the group level summary.
Many thanks Mike

Answer 1

  Hi John ,
This is better ..... Now the Text1  column is the correct duration .. Is it possible just to display the Text 1 Column instead of Duration Column ? is it a right practice in using Microsoft Project or scheduling ? This is an alternate solution
...Do you think that there is a solution to  that problem ?
Task Name
Text1
Duration
% Complete
Start
Finish
F10E ( Level 10 )
273
40d
0%
10 Apr '12
10 May '13
Hospital Admin
40
40d
0%
10 Apr '12
05 Jun '12
Hospital Move- Vacate F10E
40
40 d
0%
10 Apr '12
05 Jun '12
Eastern/Kelson
238
40d
0%
30 May '12
10 May '13
Investigate Above Ceiling Conditions
20
20 d
0%
30 May '12
26 Jun '12
Hoardings
5
5 d
0%
06 Jun '12
12 Jun '12
Demolition (All)
20
20 d
0%
20 Jun '12
18 Jul '12
HVAC- main duct Work, Fire dampers
40
40 d
0%
19 Jul '12
14 Sep '12
Layout Partitions
5
5 d
0%
19 Jul '12
25 Jul '12
Steel stud Framing & Hollow Metal Frames
30
30 d
0%
17 Sep '12
29 Oct '12
Ceiling and Bulk Head Framing
10
10 d
0%
30 Oct '12
12 Nov '12
Mechanical Rough-In to Ceiling
25
25 d
0%
13 Nov '12
17 Dec '12
Taping,Drying & Sanding
20
20 d
0%
04 Dec '12
03 Jan '13
Ceiling and Bulk Head Drywall
10
10 d
0%
04 Dec '12
17 Dec '12
Painting
15
15 d
0%
04 Jan '13
24 Jan '13
T-Bar and Acoustic Ceiling Tile With Devices
11
11 d
0%
22 Jan '13
05 Feb '13
Head Walls system
7
7 d
0%
25 Jan '13
04 Feb '13
P-Lam Corridor Canopy Ceiling
15
15 d
0%
25 Jan '13
14 Feb '13
P-Lam Corridor and Room Canopy Ceiling
10
10 d
0%
25 Jan '13
07 Feb '13
Steel Doors, Wood Doors, Hardware
15
15 d
0%
08 Mar '13
28 Mar '13