Dynamic Minimum Lag Relationship - Construction Project Scheduling and Control - page 338

at end of day 5, not day 3, its remaining duration, according to the DML
equation, would be different:

In part 2, after 10 days:

RD B ≥ [ 5 ( 1 − 0 . 40 )+ 1 ]∕ 0 . 40 = 10 ( versus 13 days )

In part 3, after 15 days:

RD B ≥ [ 10 ( 1 − 0 . 70 )+ 1 ]∕ 0 . 70 = 5 . 7 ( versus 6 . 6days )

The explanation for this observation is in the assumption of lin-
earity of activity B: if it took a number of days to reach the current
situation (AD), it will take a proportional number of days to complete
the activity (RD). With a smaller AD and constant percent complete, we
are assuming a higher productivity. Thus, the remaining duration will
be less.
3. Remember the assumption of linearity for the successor. If, however,
this assumption does not hold, as in the case where the production
rate is known to increase later, the scheduler may not use the DML rela-
tionship. Figure 12.6 shows two cases of nonlinearity of the successor,
where the DML relationship does not work.

A

A

B

B

Time

Time
Figure 12.6 Situations in which the DML relationship does not work because
the successor's production is nonlinear or linear with changing production
rates

4. he result of part 4 in Example 12.1 seems too high. It is, because
the value used for AD B includes unproductive time (days 11 through
day 15). This is generally a problem that software programs need to
address in calculating production rates (quantity/duration) and true