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Back Figure 2-14.—Network calculation. | Up Naval Construction Force/Seabee 1&C - Construction manual for building structures | Next Figure 2-16.—Level III barchart sorted by early start date. |
information to a barchart. Scheduled dates are much
easier to read on a barchart. Figure 2-16 is a level III
barchart sorted by early start date. All of the
construction activities are listed down the left-hand
side. A time scale is at the top of the page. The time
scale goes from the first workday of the project to the
last workday. The start date, finish date, and duration
of each construction activity is shown on the barchart.
The double horizontal dash lines represent critical
construction activity durations. The single dash lines
represent noncritical activity durations. Free floats are
shown as dots behind each noncritical activity. For
activities with no free float you have to look at the
activity that they are sharing floats with to find the
total float. For example, the total float for activity
4000 is shown behind activity 4005. No free float on
4000 means you cannot delay it without delaying
4005 also.
RESOURCE LEVELING
Resource leveling involves matching the construc-
tion activities scheduled to the crew size available. You
want the entire crew to be gainfully employed every
day. You also want to keep up with the scheduled work
Figure 2-15.Logic relationships.
and not fall behind. To perform resource leveling, you
need a known crew size, a time-scaled schedule, and a
histogram. The histogram shows how many people in
each rating are required on a daily basis to complete the
tasks scheduled. You can create these documents by
hand or computer. Figure 2-16 represents only the first
page of a level III barchart. Look at figure 2-16 and you
see can the resource histogram at the bottom of the page.
The numbers give the required resources needed to
complete the critical activities scheduled for each day.
These activities cannot be moved without delaying the
project!
The primary task in resource leveling is to schedule
the noncritical work as you have people to do the work.
In figure 2-17 the total float for noncritical activities
has been penciled-in in the space between the activity
numbers and descriptions. The crew sizes for each
noncritical activity also have been penciled-in next to
the activity start date. The total crew size in this example
is 7. You have resource leveled this project for a small
detachment scenario. Here the prime/sub arrangement
is not practical and extensive cross-rate use of personnel
is common.
In figure 2-18 notice the resource leveling process
was started by committing to doing the critical path as
shown and plugging in the resources. These resources
can be figured by the computer or drawn in manually
at the bottom of the page. The critical path will
obviously not keep the entire crew busy (see the
original total resource numbers at the bottom of the
page). The noncritical activities are shown on their
early start dates, but you may need to delay the start
dates if you lack the people to start the noncritical
activities at that time. If you delay the start of a
noncritical activity, you want to schedule its start as
soon as you have people (available those days where
total resources are less than 7).
Figure 2-18 has been resource leveled. The
activities were scheduled beginning with the least
amount of total float to those with the most total float.
Activity 2050 was scheduled first, then 2090, 3020,
3010, 4000, 4005, 4030, and 4010. This process
should be continued through the rest of the project.
Notice that there were not yet any personnel to
schedule for activities 2010, 2020, 2030, 7010, or
7020. These resources would be carried over to the
next page of the barchart. We also did not schedule
activities 6020, 8080, 9010, or 8095. Even though they
have the least amounts of total float, these activities
have early starts late in the project and can be
rescheduled later. Remember the activities are shown
by early start dates and can be moved forward only,
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