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 each detail.
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.
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.
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 change constantly.
You must put together realistic, workable schedules during your project's 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.
As the construction schedule unfolds, a commitment of resources (labor and equipment) fromContinue Reading