Page 16 - Estimator's Piping Man-Hour Manual 5E

6, WEATHER

Check the past weather conditions for the area in which your project is to be located. During
the months that you will be constructing what are the weather predictions based on these
past reports? Will there be much rain or snow? Will it be hot and mucky or cold arid damp?
The main items to check and analyze here are as follows:

a. Past weather reports
b. Rain or snow
c. Hot or cold

This is one of the worst of all elements to be considered. At best, all you have is a guess.
However, by giving due consideration to the items as outlined under this element your guess
will at least be based on past occurrences.

Example: Let us assume that the weather is about half good and half bad during the period
that our project is to be constructed. We must then assume a productivity range of 50% for
this element.

We have now considered and analyzed all six elements and in the examples for each individ­
ual element have arrived at a productivity efficiency percentage. Let us now group these
percentages together and arrive at a total percentage:
Productivity
Item Percentage
1. General economy 75
2. Project supervision 70
3. Labor relations 65
4. Job conditions 60
5. Equipment , 70
6. Weather ___5Q_
Total 390

Since there are six elements involved, we must now divide the total percentage by the num­
ber of elements to arrive at an average percentage of productivity.

390 ^ 6 = 65% average productivity efficiency

At this point we must caution the estimator. This example is only a guide to show a method
of arriving at a productivity percentage. By considering the preceding elements for each
individual project along with the proper man-hour tables that follow, you can make a good
labor value estimate for any place in the world at any time.

Next, we must consider the composite rate to correctly arrive at a total direct labor cost,
using the man-hours in the following tables.