CHAPTER 18 COST CONTROL

18.1 Cost Control as a Management Tool The early detection of actual or potential cost overruns (비용초과) in field construction activities is vital to management. Cost control eliminates such overruns or minimizes their impact. 원가관리 자료는 미래 견적을 위한 기초자료로 활용될 수 있다.

18.2 Project Cost Control Systems 계획 계획 대비 실적 실적 FIGURE 18.1 Steps in cost control

거래내역을 적은 원장 18.3 Cost Accounts Cost Code Cost Code 직접비 계정 간접비 계정 The first step in establishing a cost control system for a construction job is the definition of project-level cost centers. Cost center  Cost account. Cost account  Cost code.

18.4 Cost Coding Systems 건설 특성에 따라 다양한 체계 존재. 건물 건설 : MasterFormat (MF) 도로 건설 : American Road Builder (ARB)

18.4 Cost Coding Systems Figure 18.3 Detailed codes for classification within Uniform Construction Index

18.5 Project Cost Code Structure The MasterFormat code as used by the R. S. Means Building Construction Cost Data identifies four levels of detail. Level 1: 03 concrete items, Level 2: 03 11 concrete forming, Level 3: 03 11 13 structural cast-in-place concrete forming, Level 4: 03 11 13.25 forms in place      Structural cast in place concrete forms made of plywood and used once for job-built 8" × 8" columns FIGURE 18.4 UCI cost (line item) structure in the MasterFormat code

18.5 Project Cost Code Structure 1. Labor 2. Permanent materials 3. Temporary materials 4. Installed equipment 5. Expendables 6. Construction equipment 7. Supplies 8. Subcontract 9. Indirect 1. Year in which project was started (2014) 2. Project control number (15) 3. Project type (5 for power station) 4. Area code (16 for boiler house) 5. Functional division (2, indicating foundation area) 6. General work classification (0210, indicating site clearing) 7. Distribution code (6, indicating construction equipment) FIGURE 18.5 Classification of accounts: typical data structure for a computerized cost code

18.5 Project Cost Code Structure TABLE 18.1 Major Divisions in CSI’s MasterFormat Uniform Construction Index 2014 Revision  건축에 특화된 코드 체계 Construction Specifications Institute

18.6 Cost Accounts for Integrated Project Management 물리적 구성요소 Control Account 과업 Concrete tasks on foundation 1 FIGURE 18.6 Project control matrix

18.6 Cost Accounts for Integrated Project Management 필요 자원 차원 추가 과업 물리적 구성요소 FIGURE 18.7 Three-dimensional visualization of work package-oriented cost accounts

18.6 Cost Accounts for Integrated Project Management 1 2 1 0 0 2 D F 4 4 1 2 1 2 1 FIGURE 18.8 Basic cost code structure

18.6 Cost Accounts for Integrated Project Management 일정계획은 서브태스크 단위로 관리 FIGURE 18.9 Project control matrix with scheduling of subtasks

= Work Schedule - Work Performed 18.7 Earned Value Method Budgeted Cost of At Completion Budgeted Cost of Work Schedule Actual Cost of Work Performed 일정관리 (진도 느림) 원가관리 (예산 초과) = Work Schedule - Work Performed = Budgeted Cost – Actual Cost Budgeted Cost of Work Performed FIGURE 18.10 Control values for earned value analysis

FIGURE 18.11 A simple project hierarchy 18.7 Earned Value Method FIGURE 18.11 A simple project hierarchy

Actual Quantity of Work Performed 18.7 Earned Value Method Actual Quantity of Work Performed Budgeted Quantity At Completion AQWP BQAC ACWP BCWP BCAC BCACPC 종료 시점의 비용 추정치 물량 진도 진도 예산 Estimated Cost At Completion =35/105 =1000.33 =100(40/33.3) =60/77 =500.78 =50(35/39.0) =100/125 =650.80 =65(50/52.0) = 100  124.3 / 227.5 현재 생산성으로 진행되어 프로젝트가 종료되면 원래 예산 215보다 12.5가 증가한 227.5의 비용이 소요될 것으로 추정됨.

18.7 Earned Value Method 예산  실적 - 증가 : 예산 Over + 절감 : 예산 범위 내 예산/실적 > 1 : 예산 범위 내 실적  예산(계획) - 지연 : 일정 밖 + 빠름 : 일정 내

- 증가 : 예산 Over 18.7 Earned Value Method < 1 : 예산 Over - 지연 : 일정 밖 < 1 : 일정 밖 + 절감 : 예산 범위 내 > 1 : 예산 범위 내 + 빠름 : 일정 내 > 1 : 일정 내 + 절감 : 예산 범위 내 > 1 : 예산 범위 내 + 빠름 : 일정 내 FIGURE 18.12 States of control account for single project > 1 : 일정 내

18.7 Earned Value Method Cost Schedule Overrun Underrun Delay I, IV II Advantage V III, VI TABLE 18.3 Values of CPI, CV, and SPI, SV for the Six Scenarios (Singh, 1991)

FIGURE 18.13 Scenarios for permutations among ACWP, BCWP, and BCWS 18.7 Earned Value Method Cost Schedule Overrun Underrun Delay I, IV II Advantage V III, VI FIGURE 18.13 Scenarios for permutations among ACWP, BCWP, and BCWS

18.8 Labor Cost Data Collection 비용 계정 operating engineer (equipment operator) FIGURE 18.14 Foreperson’s daily labor distribution report

18.8 Labor Cost Data Collection FIGURE 18.15 Payroll data structure

18.9 Charges for Indirect and Overhead Expense Contractor-incurred expenses associated with the construction of a given facility relate to: Direct cost consumed in the realization of a physical sub-element of the project (e.g., labor and material costs involved in pouring a slab). Production support costs (Indirect cost) incurred by the project-related support resources or required by the contractor (e.g., superintendent’s salary, site office costs, various project-related insurances) costs associated with the operation and management of the company as a viable business entity (e.g., home office overhead, such as the costs associated with preparation of payroll in the home office, preparation of the estimate, marketing, and salaries of company officers).

18.10 Project Indirect Costs The contractor calculates the direct costs (as defined previously) and multiplies these charges by a percentage factor to cover both project indirects and home office fixed overhead.  직접비 : 200,000, 간접비 비율 : 20%, 간접비 = 200,000  20% = 40,000, 이윤 : 10%, 총입찰액 = 240,000 * 1.1 = 264,000 쓰레기 수거 FIGURE 18.16 Labor cost report (some typical line items)

18.11 Fixed Overhead The calculation of the home office overhead allocation factor: 전년 실적  후년 예측 부과해야할 경비 추정 부과 대상 예상 매출(직접비) 추정 부과 비율 결정 경비 : 직접비의 10% 부과

18.12 Considerations in Establishing Fixed Overhead 고정비: 간접비 성격, 변동비: 직접비 성격 PC = PS/(100 – PS) 직접비에 대한 경비 부과 비율(경비비율) = 총비용 중 경비 비중 / (100% - 총비용 중 경비 비중) PC = percentage applied to the project’s total direct cost for the coming year PS = percentage of total volume in the reference year incurred as fixed or G & A expense 경비(간접비) : 800,000, 총물량: 4,000,000, 직접비: 3,200,000 경비비율(Pc) = 800,000 / 3,200,000 = 25% Ps = 800,000 / 4,000,000 = 20% Pc = 20% / (100% -20%) = 25% 직접비: $1,000,000, 경비: $250,000, 이익률: 10% 총입찰액 = $1,000,000 + $250,000 + ($1,000,000 + $250,000)  0.1 = $1,375,000

18.12 Considerations in Establishing Fixed Overhead -25% -15% -25% 20% -15% -25% -15% Comparison of Fixed Overhead Rate Structures