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Table 2-4.—Production Efficiency Guide Factor Chart | Up
Builder Advanced - Construction manual for building structures | Next
Figure 2-15.—Construction Activity Summary Sheet (front). |
Figure 2-14.—Production efficiency graph.
The activity duration is increased by including the
availability factor to account for time lost from the
project site. The actual crew you would expect to see
on the jobsite on the average day would be the assigned
crew multiplied by the availability factor. Always use
the availability factor.
If in the drywall example, you had a crew of 12
assigned, 1 hour for lunch each day, total travel to and
from jobsite is 1 hour, and a total of 30 minutes for
breaks each day, how long would it take to complete
this task ( if the availability factor 0.75, and the
man-day equivalent is .9375)? Remember to use the
revised man-day estimate, which includes the delay
factor. The equation would be written as follows:
Duration = 70 ÷ 12 ÷ 0.75 ÷ .9375 = 8.3 or 9 workdays.
Construction Activity Summary
(CAS) Sheets
Once the master activities have been broken into
construction activities, you will need to use a CAS
sheet (figs. 2-15 and 2-16) for each activity. In addition
to the activity description and the scheduled dates, all
the required resources are shown on the front. Safety
and QC requirements are on the back. The space at the
bottom of the back page should be used for man-day
and duration calculations.
The CAS sheets should be able to stand alone. The
CAS sheets should contain all of your notes,
information, and calculations pertaining to man-days,
durations, tools, and equipment. In this way, if you are
not available, someone else can use this information
and the project can continue. It is very important that
CAS sheets be filled out correctly. Almost all of your
remaining planning is driven from the CAS sheets.
Always use a pencil to fill them out, because they
change constantly.
MATERIAL ESTIMATES
MATERIAL ESTIMATES are also used to
procure construction material for a given project, to
determine whether sufficient material is available to
construct a given project, and to determine the labor
involved to install the material. The following is a
suggested procedure for preparation of a material
estimate. First, obtain a work element checklist by
referring to the P-405, then estimate the quantity of
material needed for each activity by using the P-405
and any previous experience. Use the conversion chart
from table 2-5, whenever possible, for estimating
waste factors and the conversion of material. This
conversion should be done on a work sheet when the
estimator records how each quantity of material was
obtained. A typical material estimate work sheet is
shown in figure 2-17. Each step can readily be
understood when the work sheets are reviewed.
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