Schedule Compression and Time-Cost Trade-Off - Construction Project Scheduling and Control - page 217

optimization study, answering the question, “Is it fit or overfit?” whereas con-
structability is mostly a feasibility study, identifying obstacles and clashes during
the construction process. Second, VE covers the entire life cycle of the facil-
ity, whereas constructability focuses on the construction phase only. In both,
the participation of all involved parties is encouraged, and the earlier the study
is conducted, the better results should be expected. VE and constructability
can coexist and even complement each other (Construction Industry Institute,
1993). 6
Contracts often include a reward clause for contractors who submit cre-
ative suggestions. In such clauses, the savings are usually split between the
owner and the contractor.
Detecting and removing/managing obstacles and clashes, and improving
the design and construction efficiency will most likely help the acceleration
effort.
4. Utilizing Building Information Modeling (BIM) : The use of BIM in con-
struction projects with lean construction principles has proven to be effective in
saving time and money, improving efficiency and safety, and helping to achieve
better results in general. BIM helps “simulate” and visualize the building pro-
cess before construction takes place, to detect clashes and help improve cost,
time, productivity, safety, and other aspects of the project (see Chapter 15 for
more details), and lean construction principles increase value, minimize waste,
enhance profitability and quality, and ensure client satisfaction.
5. Work overtime—more hours per day and/or more days per week :Theresults
of some studies suggest that productivity declines with more hours worked
per week than the basic 40 hours. The Business Roundtable 7 (1980) sug-
gested an immediate, significant drop (week 1, as a result of the initial pattern
change), followed by a partial recovery (weeks 2 and 3, when the person starts
to adapt to the overtime schedule), and then a gradual, slight decline (weeks 4
through 9, as a result of work fatigue), and finally a leveling off (after weeks 9
or 10) (see Figure 8.3). RSMeans Building Construction Cost Data (RSMeans,
2010b) showed a more “linear” approach. It gave declining productivity num-
bers from week 1 to week 4. For example, for 6 days per week and 10 hours
per day, productivity was assumed to be 95%, 90%, 85%, and 80% for weeks 1
through 4, respectively. Some researchers (Larew, 1998) questioned the relia-
bility of these overtime studies.
As far as cost, overtime pay is almost always more than regular pay. If
the workers have a union contract, overtime is compensated according to the
collective bargaining agreement between the contractor and the labor union.
In most construction contracts, hours exceeding 40 per week and any hours on
Saturday are compensated at 1.5 times the regular rate. Other hours, possibly
6 You may also want to refer to the summary in two Construction Industry Institute reports (1986, 1987).
7 Now The Construction Users Roundtable (CURT).