Come up with what you feel is a reasonable delay
factor and discuss it with your chain of command. You
are not bound by either the delay factors or the
production rates in the P-405. To figure, man-day
estimates, you can use your experience to determe the
logical production rates to use. Keep in mind that the
delay factor is only used to determine the man-day
estimate for a particular construction activity. Each
activity will have a different delay factor. All other
calculations use the availability factor.
Availability factors take into account that Seabees
assigned as direct labor are not available 100 percent
of the time. The 2nd/3rd Naval Construction Brigade
provides the availability factors for planning
purposes. Availability factors are sometimes still
referred to as site efficiency factors. These factors vary
between 0.75 for mainbody sites to 0.85 for detail
sites. Using the following equation, you can determine
the man-day capability (MC) for the main body and
MC = DL x WD x ME x AF
Use DL to represent the number of direct
labor assigned, WD for the number of available
workdays, ME for the length of the workday divided
by 8 (9/8 = 1.125), and AF is the availability factor.
Multiply these four factors to figure the man-day
capability. You can use this same equation to
determine the direct labor manning for a detail if you
substitute tasked man-days for MC and plug in AF,
ME, and WD. The number of work days is taken from
the deployment calendar.
Construction Activity Durations
The MC equation also can be used to determine
construction activity durations. By substituting MD
estimated for MC, plugging in crew size (CS) for
direct labor assigned (DL), availability factor (AF),
and man-day equivalent (ME), you can solve for the
number of workdays required or project duration.
Duration = MD estimated ÷ CS ÷ AF ÷ ME
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, how long would it take to complete this task
(availability factor 0.75, man-day equivalent 1.125)?
Remember to use the revised man-day estimate. which
includes the delay factor.
Using the formula:
Duration = 70 ÷ 12 ÷ 0.75 ÷ 1.125 = 6.91 or 7.
SUMMARY (CAS) SHEETS
Once the master activities have been broken into
construction activities, you will need to use a CAS
sheet (figs. 2-9 and 2-10) for each activity. In addition
to the activity description and 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. 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
You must put together realistic, workable
schedules during your projects planning and
estimating stages if you hope to finish the tasking on
schedule during the deployment. Crucial to a workable
schedule is the proper, logical sequence of activities
and good realistic durations. Performing the forward
and backward pass will identify the critical path. The
critical path gives you a list of milestones (activity
completion dates) that must be met. If these milestones
are met, the project will be on track and finished by
the scheduled completion date.
LEVEL II ROUGHS
As the construction schedule unfolds, a
commitment of resources (labor and equipment) from