Civil Engineering Reference
In-Depth Information
Using the DML equation:
AD
B
(
1
−
PC
A
)+
L
PC
A
RD
B
≥
RD
B
≥
[
12
(
1
−
0
.
70
)+
1
]∕
0
.
70
=
6
.
6
,
say 7 days
Finish date for Activity B
=
day 22, not day 21 as calculated by the
FF relationship.
4. Assume there was work stoppage between day 10 and day 15: activity
A is still 40% complete:
Activity A:
Actual duration
=
15 days
(
including stoppage
)
Remaining duration
=
12 days
(
estimated
)
At completion duration
=
27 days
Activity B:
Actual duration
=
12 days
Remaining duration
=
13 days
(
Assuming the end of activity A
+
1day
)
Using the DML equation:
AD
B
(
1
−
PC
A
)+
L
PC
A
RD
B
=[
12
(
1
−
0
RD
B
≥
.
40
)+
1
]∕
0
.
40
=
20
.
5
,
say 21 days
Finish date for Activity B
=
day 36.
Discussion on Example 12.1
1. The DML equation is independent of the estimate of activity A's
remaining duration. Rather, it is dependent on its percent complete.
For example, in part 4 above, the scheduler may not have updated
the remaining duration of activity A, so it shows only 5 days. The DML
equation still gives the same answer for
RD
B
, that is, 21 days. This is
particularly important when production in an activity differs from reality
and the scheduler fails to adjust/update the remaining duration.
2. The DML equation is dependent, however, on the actual duration of
activity B. For example, if activity B in the previous example had started
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