Note. The percentages introduced in the last three equations represent the proportions of the TOTAL UNIT PRICES allowed for material, including the labor of receiving, but not the labor of making the forms which, for these items, is combined with the cost of erection. The computations may be simplified by the use of the slide-rule. The proportions of these amounts accredited to the various classifications are then as follows: [$3 137 X (45%4) + $123 X (454)] = $1 782 Material-Classification (1), Lum The next step is to divide the labor-items between MECHANIC LABOR and COMMON LABOR. In this case Labor-Classification (6), Receiving Lumber, will be common labor, and Labor-Classification (1), Making Forms, entirely mechanic labor. Having thus divided the allowances for constructing forms, the PRICESHEET, page 382 is again referred to, and taking the quantities from the ESTIMATE SHEETS the allowances for Placing Forms, under their several captions are tabulated as follows: All of these are to be divided between mechanic and common labor. For purpose of demonstration assume a ratio of 3 to 2. The remaining estimate-units used upon the minor portions of form-work include the entire labor of making as well as placing. For these items the material has already been taken out and the remainder of the estimate-figure can now be used as a LABOR-ALLOWANCE. These items are as follows, tabulated from the PRICE-SHEET. Stairs, $1.00 less 15% for material = = $0.85 × 143 lin ft = $122, Labor-Classification (14) Window Sills, $0.75 less 20% for material = $0.60 × 530 lin ft = $318, Labor Classification (15) Roof Parapet Coping, $0.40 less 20% for material = $0.32 X 270 lin ft = $86, Labor-Classification (17) All of these are divided between mechanic labor and common labor, in the ratio of 3 to 2. This completes the analysis of FORM-WORK, and the items appear properly arranged on the ANALYSIS-SHEETS, pages 482 to 486. 3. Concrete. From the PRICE-SHEET, page 382, Cement, 1.60($3 +0.15 +0.08) Sand, 0.45(1.50 +0.20) = $5.17 = 0.76 This gives the component parts of the ESTIMATE-PRICE. As all the concrete, 15 330 cu ft, has already been summarized under one heading on the ESTIMATESHEET, this total allowance, $6 745, has merely to be divided in the same proportion as the total $11.75 is divided in the estimate. Crushed stone, 0.90 × 2.60 × (6 745/11.75) = 1 340 Material-Classification (4) Receiving Crushed Stone, 0.90 X 0.26 X (6 745/11.75) Power, 0.15 X (6 745/11.75) Water, 0.10 X (6 745/11.75) Labor, 3.00 X (6 745/11.75) Total = = = 135 Labor-Classification (7) 85 Material-Classification (17) 60 Material Classification (19) 1 725 Labor-Classification (13) $6 745 Having thus divided the concrete-allowance into its component parts of labor and material, the next step is to run through the other items of the estimate, picking out the cement, sand, and gravel, under classifications other than concrete. For example, under floor-finish, brick curtain walls, terra-cotta partitions and cinder concrete, there is a total of 163 bbls of cement the total allowance for this material delivered, including receiving, is $527, which amount is divided in the same way into cost at job-siding, receiving, bag loss and testing. Similarly the remaining allowances for each material are added and then subdivided into their various constituent parts which are recorded under the appropriate labor or material classification. 4. Steel Reinforcement. From the ESTIMATE-SHEET the total allowance for all reinforcement is taken as $3 143. From the PRICE-RECORD, page 385: Reinforcement = $3.00 +0.20 + 0.40 +0.10 +1.25 = $4.95 per 100 lb or $0.0495 per lb This unit is then divided by the same method into Reinforcement (f.o.b. cars destination, including average extras) $2 283, Material Classification (6) 3.60 × 3 143/4.95 = 5. Remaining Estimate-Items. These are broken up by the same method, with the results shown on the ANALYSIS-SHEETS, pages 482 to 486. As a guide in dividing the several items of OVERHEAD CHARGES between labor and material, the following ratios are given: Installation, 55% Labor, 45% Material; Cutting, Pointing and Cleaning, 80% Labor, 20% Material; General Expense, 75% Labor, 25% Material. The subcontracts do not require analysis, but should be recorded on a separate sheet following the labor and material. The analysis closes with a SUMMARY-SHEET showing the totals of labor, material, and subcontracts, with the additional items of Office-Expense, PlantRental, and Profit or Commission. Certain items, such as Fire Insurance and Liability Insurance, which are included under Materials, are to be particularly noted. 4. THE INDICATED OUTCOME 1. Purpose. From a comparison of UNIT COSTS alone, the actual against the estimated, the efficiency of the individual job operations can be judged; but in order to gain a clear conception of the effect which these costs have upon the ENTIRE JOB as a business venture, it is necessary to reestimate the cost of the TOTAL QUANTITY OF WORK in the various classifications, using the units derived from the PARTIAL ACCOMPLISHMENT to date. In this manner, after a reliable unit has been determined for the major classifications, it is quite possible Such reports are to obtain a definite forecast of the outcome for the entire job. not only a most valuable element of service to an owner in cost-plus work, but they also enable a builder to form a clearer conception of the work as a whole, and furnish him with much valuable information in case his own money is at stake. 2. Method and Procedure. Having the ESTIMATE-ANALYSIS at hand, together with a list of the AVERAGE LABOR-UNITS which the job has made to date, and the AVERAGE MATERIAL-PRICES from the MATERIAL-DISTRIBUTION ACCOUNT or the INVOICES, the computation of the indicated cost for each classification is made by multiplying the total estimated or revised quantities by a unit based upon the cost to date. It is not necessary or practicable to run through all the items of an estimate and to attempt a complete revision; but the INDICATED OUTCOME is developed at intervals as the work progresses by making a detailed comparison between estimated and indicated costs, picking up each classification as soon as authentic data are obtained in the form of reasonably representative labor-units and actual purchase-prices for materials and subcontract-work. The estimate is considered correct until proven otherwise, and the reports do not include the complete list of classifications until the end of the job is approached. In this connection it should be borne in mind that the omission of classifications upon which sufficient data are not available to warrant a comparison, is merely equivalent to an assumption that the estimate is correct for such items. The object is to determine a value which will be the probable total cost of the job; and this is accomplished, as indicated on the SUMMARY-SHEET, by starting with the original estimate plus the subsequent estimates for extras, and adding or subtracting the probable loss or gain as indicated by the work done to date. The principles involved in these computations are very simple, but the work requires care in execution, and the ESTIMATE-ANALYSIS must be revised to include all additions, subtractions, or alterations in the original estimate. The labor-units on the cost-reports will not be affected by such omissions, as they are computed from actual quantities placed; but the estimated allowances will eventually be in error and show an erroneous loss or gain as soon as they are extended for comparison. The INDICATED OUTCOME may, of course, be made at any desired intervals; but the dates must coincide with the termination of the cost-periods. 3. Arrangement of the Report. The body of the report is divided into labor, materials, and subcontracts, to which is added a SUMMARY-SHEET. In the left-hand column of the report is entered the classification of the item. The second column contains the estimate-allowance; quantity, unit price and amount, in dollars. In the third column are the values representing the total indicated cost, also expressed in quantity, unit price, and amount. The fourth and fifth columns record the Loss and Gain, respectively. This arrangement is the same for each of the three parts, labor, material, and subcontracts. 4. Indicated Labor-Costs. For all classifications having units, such as forms, concrete, excavation, etc., the total indicated cost is computed by multiplying the quantity of work done to date by its average labor-unit, and adding the product obtained by multiplying the quantity of work still to be done by a unit based upon the cost to date. (13) Con- Extra No. 21, crete 40 cu ydX 3.20= 566 526 cu ydX$3.00=$1 578 400 cu ydX$3.20=$1 280| $1 811 It is to be noted that in computing the INDICATED COST, the work actually done, 400 cu yd, should always be kept separate from that remaining to be. done, 126 cu yd, even if, as in this case, the unit is considered to be the same; this is in order to indicate the proportion of each classification uncompleted. It is also desirable to give the reason when a different unit is used for the uncompleted work. Upon the ability shown in choosing the unit for the balance of each operation depends the accuracy of the report. All elements likely to influence the cost of the work should be carefully considered, such as the possibility of change in labor-rates, greater difficulty in executing the final portions of the work, the cost of breaking up forms, baling cement-bags, etc. Furthermore, little faith can be placed in a unit until it is based upon considerable typical work, and a |