Page 244 - Industrial Process Plant Construction Estimating and Man Hour Analysis

222 Industrial Process Plant Construction Estimating and Man-Hour Analysis

11.2 Industrial process plant construction estimating process
Process plant labor estimating is a process that includes the four steps:

(1) The first step starts with the quantity takeoff, field-specific scope.
(2) Step two converts the field-specific scope to quantities using the compar-
ison method; takeoff represents the complete scope of work.
(3) The third step is the application of man-hour units to the quantified scope of
work. The man-hour data tables have been developed from historical data,
collected from field cost reports, and verified using graphic and regression
analysis.
(4) Final step is to enter the unit man-hour rates from the tables and the quan-
tities from the “takeoff” into the estimate sheet and calculate the direct craft
man-hours using the unit quantity method (man-hour rate “takeoff” quan-
tities). The estimate man-hours are compared with the historical man-hours.

11.3 Sample estimate construction estimating process

Table 11.3.1 Example field erection fan inlet cowl and fan screens
(1) The first step starts with the quantity takeoff, field-specific scope.
Fan inlet cowl and fan screens
Fan screen supports
Fan screen modules
Mount fan cowl segments and top ring
Bolt connection
Install fan deck plates
(2) Convert the field-specific scope to quantities using the comparison method.
(3) The third step is the application of man-hour units to the quantified scope of
work. The man-hour data tables have been developed from historical data,
collected from field cost reports, and verified using graphic analysis.

TABLE 11.3.1 MHₔ 5 estimate for increased fan inlet cowl and fan screens
quantities
Estimate—ACC-solar power plant-fan inlet Historical Estimate
cowl screen
Description Qty Unit Qty Unit
Fan inlet cowl and fan screens
Fan screen supports 12.00 EA 15.00 EA
Fan screen modules 5.00 EA 6.25 EA
Mount fan cowl segments and top ring 12.00 EA 15.00 EA
Bolt connection 36.00 EA 45.00 EA
Install fan deck plates 12.00 EA 15.00 EA