Civil Engineering Reference Manual for PE Exam PDF

86 Project Management,...

86 Project Management, Budgeting, and Scheduling................................................................................................................................................................................................................................................................................. 1. Project Management..................... 86-1 software, and many other industries. The PMBOK Guide 2. Budgeting.............................. 86-2 is process-based, meaning it describes projects as being 3. Scheduling.............................. 86-8 the outcome of multiple processes. Processes overlap and 4. Resource Leveling....................... 86-10 interact throughout the various phases of a project. Each 5. Activity-on-Node Networks.............. 86-11 process occurs within one of five process groups, which 6. Solving a CPM Problem................. 86-11 are related as shown in Fig. 86.1. The five PMBOK 7. Activity-on-Arc Networks................ 86-12 process groups are (1) initiating, (2) planning, (3) con- 8. Stochastic Critical Path Models.......... 86-14 trolling and monitoring, (4) executing, and (5) closing. 9. Monitoring............................. 86-15 10. Coordinating............................ 86-15 11. Documentation.......................... 86-16 Figure 86.1 PMBOK Process Groups 12. Earned Value Method................... 86-16 Nomenclature initiating planning D duration EF earliest finish ES earliest start LF latest finish controlling and LS latest start executing monitoring t time z standard normal variable Symbols closing
mean  standard deviation The PMBOK Guide identifies nine project management 1. PROJECT MANAGEMENT................................................................................................................................. knowledge areas that are typical of nearly all projects. Project management is the coordination of the entire The nine knowledge areas and their respective processes process of completing a job, from its inception to final are summarized as follows. move-in and post-occupancy follow-up. In many cases, 1. Integration: develop project charter, project scope project management is the responsibility of one person. statement, and management plan; direct and manage Large projects can be managed with partnering. With execution; monitor and control work; integrate this method, the various stakeholders of a project, such change control; close project as the architect, owner, contractor, engineer, vendors, and others are brought into the decision making process. 2. Scope: plan, define, create work breakdown structure Partnering can produce much closer communication on (WBS), verify, and control scope a project and shared responsibilities. However, the day- 3. Time: define, sequence, estimate resources, and esti- to-day management of a project may be difficult with so mate duration of activities; develop and control many people involved. A clear line of communications schedule and delegation of responsibility should be established and agreed to before the project begins. 4. Cost: estimate, budget, and control costs and Professional Systems, Mgmt, Many project managers follow the procedures outlined in 5. Quality: plan; perform quality assurance and quality A Guide to the Project Management Body of Knowledge control (PMBOK Guide), published by the Project Management 6. Human Resources: plan; acquire, develop, and man- Institute. The PMBOK Guide is an internationally recog- age project team nized standard (IEEE Std 1490) that defines the funda- mentals of project management as they apply to a wide 7. Communications: plan; distribute information; report range of projects, including construction, engineering, on performance; manage stakeholders P P I * w w w. p p i 2 p a s s. c o m  86-2 C I V I L E N G I N E E R I N G R E F E R E N C E M A N U A L 8. Risk: identify risks; plan risk management and information, see the “Time-Cost Trade-Off” section in response; perform qualitative and quantitative risk this chapter. In some cases, value engineering can be analysis; monitor and control performed during which individual systems and mate- rials are reviewed to see if the same function can be 9. Procurement: plan purchases, acquisitions, and con- accomplished in a less expensive way. tracts; request seller responses; select sellers; admin- ister and close contracts Fee Projections Each of the processes also falls into one of the five basic process groups, creating a matrix so that every process A fee projection is one of the earliest and most impor- is related to one knowledge area and one process group. tant tasks that a project manager must complete. A fee Additionally, processes are described in terms of inputs projection takes the total fee the designer will receive for (documents, plans, designs, etc.), tools and techniques the project and allocates it to the schedule and staff (mechanisms applied to inputs), and outputs (docu- members who will work on the project, after deducting ments, products, etc.). amounts for profit, overhead, and other expenses that will not be used for professional time. Establishing a budget (knowledge area 4) and scheduling design and construction (knowledge area 3) are two of the Ideally, fee projections should be developed from a care- most important parts of project management because ful projection of the scope of work, its associated costs they influence many of the design decisions to follow (direct personnel expenses, indirect expenses, and over- and can determine whether a project is even feasible. head), consultant fees, reimbursable expenses, and profit desired. These should be determined as a basis for setting the final fee agreement with the client. If this is done correctly, there should be enough money to 2. BUDGETING................................................................................................................................. complete the project within the allotted time. Budgets may be established in several ways. For spec- There are many methods for estimating and allocating ulative or for-profit projects, the owner or developer fees. Figure 86.2 shows a simple manual form that com- works out a pro forma statement listing the expected bines time scheduling with fee projections. In this income of the project and the expected costs to build it. example, the total working fee, that is, the fee available An estimated selling price of the developed project or to pay people to do the job after subtracting for profit, rent per square foot is calculated and balanced against consultants, and other expenses, is listed in the upper all the various costs, one of which is the construction right corner of the chart. The various phases or work price. In order to make the project economically feasible, tasks needed to complete the job are listed in the left- there will be a limit on the building costs. This becomes hand column, and the time periods (most commonly in the budget within which the work must be completed. weeks) are listed across the top of the chart. Budgets for municipal and other public projects are The project manager estimates the percentage of the often established through public funding or legislation. total amount of work or fee that he or she thinks each In these cases, the construction budget is often fixed phase will require. This estimate is based on experience without the architect’s or engineer’s involvement, and and any common rules of thumb the design or construc- the project must be designed and built for the fixed tion office may use. The percentages are placed in the amount. Unfortunately, when public officials estimate third column on the right and multiplied by the total the cost to build a project, they sometimes neglect to working fee to get the allotted fee for each phase (the include all aspects of development, such as professional figure in the second column on the right). This allotted fees, furnishings, and other items. fee is then divided among the number of time periods in the schedule and placed in the individual columns under Budgets may also be based on the proposed project each time period. specifics. This is the most realistic and accurate way to establish a preliminary budget because it is based on the If phases or tasks overlap (as they do in Fig. 86.2), sum actual characteristics of the project. However, this the fees in each period and place this total dollar method assumes funding will be available for the project amount at the bottom of the chart. The total dollar as designed. amount can then be divided by an average billing rate for the people working on the project to determine an There are four basic variables in developing any con- approximate budgeted number of hours that the office struction budget: quantity, quality, available funds, can afford to spend on the project each week and still and time. There is always a balance among these four and Professional make a profit. Of course, if the number of weekly hours Systems, Mgmt, variables, and changing one or more affects the others. exceeds about 40, then more than one person will be For instance, if an owner needs a certain area (quan- needed to do the work. tity), needs the project built at a certain time, and has a fixed amount of money to spend, then the quality of By monitoring time sheets, the project manager can construction will have to be adjusted to meet the other compare the actual hours (or fees) expended against constraints. If time, quality, and the total budget are the budgeted time (or fees) and take corrective action fixed, then the area must be adjusted. For more if actual time exceeds budgeted time. P P I * w w w. p p i 2 p a s s. c o m  P R O J E C T M A N A G E M E N T , B U D G E T I N G , A N D S C H E D U L I N G 86-3 Figure 86.2 Fee Projection Chart Project: Mini-mall Project No.: 9274 Date: 10/14/2012 Completed by: JBL Project Manager: JBL Total Fee: $26,400 Period 1 2 3 4 5 6 7 8 9 fee % of allocation person-hrs total by phase est. Phase or Task Date 11/16-22 11/23 11/30 12/7 12/14 12/21 12/28 1/4 1/11 fee or task SD—design 1320 1320 10 2640 SD—presentation 1320 5 1320 DD—arch. work 1980 1980 15 3960 DD—consultant coord. 530 790 1320 5 DD—approvals 1320 5 1320 1056 1056 1056 1056 1056 CD—plans/elevs. 20 5280 CD—details 2640 2640 20 5280 440 440 440 5 CD—consultant coord. 1320 1320 1320 10 CD—specs. 2640 CD—material sel. 660 660 5 1320 budgeted fees/period 1320 2640 2510 4090 2156 1716 4136 5456 2376 100% $26,400 person-weeks or hours 53 1.3 106 2.6 100 2.5 164 4 108 2.7 86 2.2 207 5 273 6.8 119 3 JLK JLK AST JLK AST JLK AST JLK AST JLK JLK AST JLK SBS JLK AST staff assigned JBC EMW-(1/2) JBC EMW EMW AST EMW BFD EMW actual fees expended Quality planning involves determining with the client completing standard estimating forms, filling in dimen- what the expectations are concerning design, cost, and sions, numbers of units, and other information. Table 86.1 other aspects of the project. Quality does not simply is a small part of a larger takeoff report illustrating the mean high-cost finishes, but rather the requirements of degree of detail needed to estimate the project cost. A the client based on his or her needs. These needs should cost estimator working for a general contractor, for be clearly defined in the programming phase of a project example, uses a construction project’s plans and specifi- and written down and approved by the client before cations to estimate the materials dimensions and count design work begins. the quantities of all items associated with the project. Cost Estimating Though the quantity takeoff process can be done manu- ally using a printout, a red pen, and a clicker, it can also Estimators compile and analyze data on all of the fac- be done with a digitizer that enables the user to take tors that can influence costs, such as materials, labor, measurements from paper bid documents, or with an location, duration of the project, and special machinery integrated takeoff viewer program that interprets elec- requirements. The methods for estimating costs can tronic bid documents. In any case, the objective is to differ greatly by industry. On a construction project, generate a set of takeoff elements (counts, measure- for example, the estimating process begins with the ments, and other conditions that affect cost) that is used decision to submit a bid. After reviewing various pre- to establish cost estimates. Table 86.1 is an example of a liminary drawings and specifications, the estimator vis- typical quantity take-off report for lumber needed for a its the site of the proposed project. The estimator needs construction project. to gather information on access to the site; the avail- Although subcontractors estimate their costs as part of and Professional ability of electricity, water, and other services; and sur- Systems, Mgmt, face topography and drainage. The estimator usually their own bidding process, the general contractor’s cost records this information in a signed report that is estimator often analyzes bids made by subcontractors. included in the final project estimate. Also during the takeoff process, the estimator must make decisions concerning equipment needs, the After the site visit, the estimator determines the quantity sequence of operations, the size of the crew required, of materials and labor the firm will need to furnish. This and physical constraints at the site. Allowances for process, called the quantity survey or “takeoff,” involves wasted materials, inclement weather, shipping delays, P P I * w w w. p p i 2 p a s s. c o m  86-4 C I V I L E N G I N E E R I N G R E F E R E N C E M A N U A L Table 86.1 Partial Lumber and Hardware Take-Off Report total size description usage pieces length foundation framing 2
4 DF STD/BTR stud 38 8 2
6 DF #2/BTR stud 107 8 2
6 PTDF mudsill – RL 2
6 DF #2/BTR bracing – RL 2
4 DF STD/BTR blocking – RL 117=8 ″ TJI/250 floor joist 11 18 117=8 ″ TJI/250 floor joist 12 10 2
4 DF STD/BTR plate – RL 2
6 DF #2/BTR plate – RL 4
4 PTDF posts 7 4 4
6 PTDF posts 23 4 6
6 PTDF posts 1 4 2
12 DF #2/BTR rim – RL 15= 4
8 32 ″ CDX plywood subfloor 12 pre-cut doors 31=2 ″
71=4 ″ LVL header 1 100″ 31=2 ″
71=4 ″ LVL header 1 130″ 31=2 ″
71=4 ″ LVL header 10 24″ exterior sheathing and shearwall 1= 2″ CDX plywood shear wall 100 4
8 1= 2″ CDX plywood exterior sheathing 89 4
8 roof sheathing 1= 2″ CDX plywood roof sheathing 67 4
8 building A & B hardware Simpson HD64 6 pieces each Simpson HD22 23 pieces each and other factors that may increase costs also must be project), cost estimators use a computer database con- incorporated in the estimate. After completing the taining information on the costs and conditions of many quantity surveys, the estimator prepares a cost sum- other similar projects. Although computers cannot be mary for the entire project, including the costs of labor, used for the entire estimating process, they can relieve equipment, materials, subcontracts, overhead, taxes, estimators of much of the drudgery associated with insurance, markup, and any other costs that may affect routine, repetitive, and time-consuming calculations. the project. The chief estimator then prepares the bid proposal for submission to the owner. Construction cost estimators also may be employed by the project’s archi- Cost Influences tect or owner to estimate costs or to track actual costs relative to bid specifications as the project develops. There are many variables that affect project cost. Con- struction cost is only one part of the total project devel- Estimators often specialize in large construction compa- opment budget. Other factors include such things as site nies employing more than one estimator. For example, acquisition, site development, fees, and financing. one may estimate only electrical work and another may Table 86.2 lists most of the items commonly found in a concentrate on excavation, concrete, and forms. project budget and a typical range of values based on and Professional Systems, Mgmt, construction cost. Not all of these are part of every Computers play an integral role in cost estimation development, but they illustrate the things that must because estimating often involves numerous mathemat- be considered. ical calculations requiring access to various historical databases. For example, to undertake a parametric Building cost is the money required to construct the analysis (a process used to estimate costs per unit based building, including structure, exterior cladding, finishes, on square footage or other specific requirements of a and electrical and mechanical systems. Site development P P I * w w w. p p i 2 p a s s. c o m  P R O J E C T M A N A G E M E N T , B U D G E T I N G , A N D S C H E D U L I N G 86-5 Table 86.2 Project Budget Line Items line item example A site acquisition $1,100,000 B building costs area times cost per ft2 (assume) $6,800,000 C site development 10% to 20% of B (15%) $1,020,000 D total construction cost B+C $7,820,000 E movable equipment 5% to 10% of B (5%) $340,000 F furnishings $200,000 G total construction and furnishings D+E+F $8,360,000 H professional services 5% to 10% of D (7%) $547,400 I inspection and testing $15,000 J escalation estimate 2% to 20% of G per year (10%) $836,000 K contingency 5% to 10% of G (8%) $668,800 L financing costs $250,000 M moving expenses (assume) $90,000 N total project budget G + H through M $11,867,200 costs are usually a separate item. They include such loan origination fees, construction loan interest, and things as parking, drives, fences, landscaping, exterior other administrative costs. On long-term loans, the cost lighting, and sprinkler systems. If the development is of financing can easily exceed all of the original building large and affects the surrounding area, a developer and development costs. In many cases, long-term inter- may be required to upgrade roads, extend utility lines, est, called debt service, is not included in the project and do other major off-site work as a condition of get- budget because it is an ongoing cost to the owner, as are ting approval from public agencies. maintenance costs. Movable equipment and furnishings include furniture, Finally, many clients include moving costs in the devel- accessories, window coverings, and major equipment opment budget. For large companies and other types of necessary to put the facility into operation. These are clients, the money required to physically relocate, often listed as separate line items because the funding including changing stationery, installing telephones, for them may come out of a separate budget and and the like, can be a substantial amount. because they may be supplied under separate contracts. Methods of Budgeting Professional services are architectural and engineering fees as well as costs for such things as topographic The costs described in the previous section and shown in surveys, soil tests, special consultants, appraisals and Table 86.2 represent a type of budget done during pro- legal fees, and the like. Inspection and testing involve gramming or even prior to programming to test the money required for special on-site, full-time inspection feasibility of a project. The numbers are preliminary, (if required), and testing of such things as concrete, often based on sketchy information. For example, the steel, window walls, and roofing. building cost may simply be an estimated cost per square foot multiplied by the number of gross square Because construction takes a great deal of time, a factor feet needed. The square footage cost may be derived for inflation should be included. Generally, the present from similar buildings in the area, from experience, or budget estimate is escalated to a time in the future at from commercially available cost books. the expected midpoint of construction. Although it is impossible to predict the future, by using past cost Budgeting, however, is an ongoing activity. At each indexes and inflation rates and applying an estimate to stage of the design process, there should be a revised the expected condition of the construction, the architect budget reflecting the decisions made to that time. As can usually make an educated guess. shown in the example, pre-design budgets are usually based only on area, but other units can also be used. For A contingency cost should also be added to account for example, many companies have rules of thumb for mak- unforeseen changes by the client and other conditions ing estimates based on cost per hospital bed, cost per that add to the cost. For an early project budget, the student, cost per hotel room, or similar functional units. and Professional Systems, Mgmt, percentage of the contingency should be higher than contingencies applied to later budgets, because there After the pre-programming budget, the architect usu- are more unknowns. Normally, 5% to 10% should be ally begins to concentrate on the building and site devel- included. opment costs. At this stage an average cost per square foot may still be used, or the building may be divided Financing includes not only the long-term interest paid into several functional parts and different square foot- on permanent financing but also the immediate costs of age prices may be assigned to each part. A school, for P P I * w w w. p p i 2 p a s s. c o m  86-6 C I V I L E N G I N E E R I N G R E F E R E N C E M A N U A L example, may be classified into classroom space, labora- budget, the architect and the client can review the tory space, shop space, office space, and gymnasium parameter estimate and decide, for example, that some space, each having a different cost per square foot. This wood flooring must be replaced with less expensive car- type of division can be developed concurrently with the peting. Similar decisions can be made concerning any of programming of the space requirements. the parameters in the budget. During schematic design, when more is known about the Another way to compare and evaluate alternative con- space requirements and general configuration of the struction components is with matrix costing. With this building and site, system budgeting is based on major technique, a matrix is drawn showing, along one side, the subsystems. Historical cost information on each type of various alternatives and, along the other side, the indi- subsystem can be applied to the design. At this point it vidual elements that combine to produce the total cost of is easier to see where the money is being used in the the alternatives. For example, in evaluating alternatives building. Design decisions can then be based on studies for workstations, all of the factors that would comprise of alternative systems. A typical subsystem budget is the final cost could be compared. These factors might shown in Table 86.3. include the cost of custom-built versus pre-manufactured workstations, task lighting that could be planned with custom-built units versus higher-wattage ambient light- Table 86.3 System Cost Budget of Office Buildings ing, and so on. average cost Parameter line items are based on commonly used units subsystem ($/ft2) (% of total) that relate to the construction element under study. For foundations 3.96 5.2 instance, a gypsum board partition would have an floors on grade 3.08 4.0 assigned cost per square foot of complete partition of a superstructure 16.51 21.7 particular construction type rather than separate costs roofing 0.18 0.2 for metal studs, gypsum board, screws, and finishing. exterior walls 9.63 12.6 There would be different costs for single-layer gypsum partitions 5.19 6.8 board partitions, 1-hr rated walls, 2-hr rated walls, and wall finishes 3.70 4.8 other partition types. floor finishes 3.78 5.0 ceiling finishes 2.79 3.7 Overhead and Profit conveying systems 6.45 8.5 specialties 0.70 0.9 Two additional components of construction cost are the fixed equipment 2.74 3.6 contractor’s overhead and profit. Overhead can be HVAC 9.21 12.1 further divided into general overhead and project over- plumbing 3.61 4.6 head. General overhead is the cost to run a contracting electrical 4.68 6.1 business, and involves office rent, secretarial help, heat, and other recurring costs. Project overhead is the money 76.21 100.0 it takes to complete a particular job, not including labor, materials, or equipment. Temporary offices, pro- ject telephones, sanitary facilities, trash removal, insur- Values for low-, average-, and high-quality construction ance, permits, and temporary utilities are examples of for different building types can be obtained from cost project overhead. The total overhead costs, including databases and published estimating manuals and applied both general and project expenses, can range from about to the structure being budgeted. The dollar amounts 10% to 20% of the total costs for labor, materials, and included in system cost budgets usually include markup equipment. for contractor’s overhead and profit and other construc- tion administrative costs. Profit is the last item a contractor adds onto an esti- mate and is listed as a percentage of the total of labor, During the later stages of schematic design and early materials, equipment, and overhead. This is one of the stages of construction documents, more detailed esti- most highly variable parts of a budget. Profit depends mates are made. The procedure most often used is the on the type of project, its size, the amount of risk parameter method, which involves an expanded item- involved, how much money the contractor wants to ization of construction quantities and assignment of unit make, the general market conditions, and, of course, costs to these quantities. For example, instead of using whether or not the job is being bid. one number for floor finishes, the cost is broken down into carpeting, vinyl tile, wood strip flooring, unfinished During extremely difficult economic conditions, a con- and Professional Systems, Mgmt, concrete, and so forth. Using an estimated cost per tractor may cut the profit margin to almost nothing square foot, the cost of each type of flooring can be simply to get the job and keep his or her workforce estimated based on the area. With parametric budget- employed. If the contract is being negotiated with only ing, it is possible to evaluate the cost implications of one contractor, the profit percentage will be much higher. each building component and to make decisions con- In most cases, however, profit will range from 5% to 20% cerning both quantity and quality in order to meet the of the total cost of the job. Overall, overhead and profit original budget estimate. If floor finishes are over can total about 15% to 40% of construction cost. P P I * w w w. p p i 2 p a s s. c o m  P R O J E C T M A N A G E M E N T , B U D G E T I N G , A N D S C H E D U L I N G 86-7 Cost Information Life-Cycle Cost Analysis One of the most difficult aspects of developing project Life-cycle cost analysis (LCC) is a method for deter- budgets is obtaining current, reliable prices for the kinds mining the total cost of a building or building compo- of construction units being used. There is no shortage of nent or system over a specific period of time. It takes commercially produced cost books that are published into account the initial cost of the element or system yearly. These books list costs in different ways; some under consideration as well as the cost of financing, are very detailed, giving the cost for labor and materials operation, maintenance, and disposal. Any residual for individual construction items, while others list value of the components is subtracted from the other parameter costs and subsystem costs. The detailed price costs. The costs are estimated over a length of time listings are of little use to architects because they are too called the study period. The duration of the study specific and make comparison of alternate systems period varies with the needs of the client and the difficult. useful life of the material or system. For example, investors in a building may be interested in comparing There are also computerized cost estimating services various alternate materials over the expected invest- that only require the architect or engineer to provide ment time frame, while a city government may be general information about the project, location, size, interested in a longer time frame representing the major materials, and so forth. The computer service expected life of the building. All future costs are dis- then applies its current price database to the informa- counted back to a common time, usually the base tion and produces a cost budget. Many architects and date, to account for the time value of money. The engineers also work closely with general contractors to discount rate is used to convert future costs to their develop a realistic budget. equivalent present values. Commercially available cost information, however, is the Using life-cycle cost analysis allows two or more alter- average of many past construction projects from around natives to be evaluated and their total costs to be the country. Local variations and particular conditions compared. This is especially useful when evaluating may affect the value of their use on a specific project. energy conservation measures where one design alter- native may have a higher initial cost than another, Two conditions that must be accounted for in develop- but a lower overall cost because of energy savings. ing any project budget are geographical location and Some of the specific costs involved in an LCC of a inflation. These variables can be adjusted by using cost building element include the following. indexes that are published in a variety of sources, including the major architectural and construction trade magazines. Using a base year as index 1000, for. initial costs, which include the cost of acquiring and example, for selected cities around the country, new installing the element indexes are developed each year that reflect the increase in costs (both material and labor) that year.. operational costs for electricity, water, and other utilities The indexes can be used to apply costs from one part of the country to another and to escalate past costs to the. maintenance costs for the element over the length of expected midpoint of construction of the project being the study period, including any repair costs budgeted.. replacement costs, if any, during the length of the study period Example 86.1. finance costs required during the length of the study The cost index in your city is 1257 and the cost index for period another city in which you are designing a building is 1308. If the expected construction cost is $1,250,000. taxes, if any, for initial costs and operating costs based on prices for your city, what will be the expected cost in the other region? The residual value is the remaining value of the ele- Solution ment at the end of the study period based on resale value, salvage value, value in place, or scrap value. All cost A cost B of the costs listed are estimated, discounted to their ¼ present value, and added together. Any residual value index A index B

 is discounted to its present value and then subtracted and Professional Systems, Mgmt, cost in index in your city cost from the total to get the final life-cycle cost of the other region ¼ other region your city index element.
 $1;250;000 A life-cycle cost analysis is not the same as a life-cycle ¼ ð1308Þ 1257 assessment (LCA). An LCA analyzes the environmental ¼ $1;300;716 impact of a product or building system over the entire life of the product or system. P P I * w w w. p p i 2 p a s s. c o m  86-8 C I V I L E N G I N E E R I N G R E F E R E N C E M A N U A L 3. SCHEDULING................................................................................................................................. coordination problem, and for some phases only a few people are needed, even for very large jobs. There are two primary elements that affect a project’s. Abilities and design methodology of the project team: schedule: design sequencing and construction sequenc- ing. The architect has control over design and the pro- Younger, less-experienced designers will usually need duction of contract documents, while the contractor has more time to do the same amount of work than control over construction. The entire project should be would more senior staff members. scheduled for the best course of action to meet the. Type of client, client decision-making, and approval client’s goals. For example, if the client must move by processes of the client: Large corporations or public a certain date and normal design and construction agencies are likely to have a multilayered decision- sequences make this impossible, the engineer, architect, making and approval process. Getting necessary or contractor may recommend a fast-track schedule or information or approval for one phase from a large some other approach to meet the deadline. client may take weeks or even months, while a small, single-authority client might make the same decision in a matter of days. Design Sequencing Prior to creating a design, the architect needs to gather The construction schedule may be established by the information about a client’s specific goals and objec- contractor or construction manager, or it may be esti- tives, as well as analyzing any additional factors that mated by the architect during the programming phase may influence a project’s design. (This gathering of so that the client has some idea of the total time information is known as programming.) required from project conception to move-in. Once this preliminary information has been gathered, Many variables can affect construction time. Most can the design process may begin. The design process nor- be controlled in one way or another, but others, like mally consists of several clearly defined phases, each of weather, are independent of anyone’s control. Beyond which must be substantially finished and approved by the obvious variables of size and complexity, the follow- the client before the next phase may begin. These phases ing is a partial list of some of the more common are outlined in the “Owner-Architect Agreement,” variables. which is published by the American Institute of Archi- tects (AIA), as well as in other AIA documents. The. management ability of the contractor to coordinate architectural profession commonly refers to the phases the work of direct employees with that of any as follows. subcontractors 1. Schematic Design Phase: develops the general layout. material delivery times of the project through schematic design drawings, along with any preliminary alternate studies for. quality and completeness of the architect’s drawings materials and building systems and specifications 2. Design Development Phase: refines and further devel-. weather ops any decisions made during the schematic design. labor availability and labor disputes phase; preliminary or outline specifications are writ- ten and a detailed project budget is created. new construction or remodeling (remodeling gener- ally takes more time and coordination than for new 3. Construction Documents Phase: final working draw- buildings of equal areas) ings, as well as the project manual and any bidding or contract documents, are solidified. site conditions (construction sites or those with sub- 4. Bidding or Negotiation Phase: bids from several con- surface problems usually take more time to build on) tractors are obtained and analyzed; negotiations with. characteristics of the architect (some professionals a contractor begin and a contractor is selected are more diligent than others in performing their 5. Construction Phase: see the following section, duties during construction) “Construction Sequencing”. lender approvals The time required for each of these five phases is highly. agency and governmental approvals variable and depends on the following factors.. Size and complexity of the project: A 500,000 ft2 and Professional Systems, Mgmt, (46 450 m2) hospital will take much longer to design Construction Sequencing than a 30,000 ft2 (2787 m2) office building. Construction sequencing involves creating and following. Number of people working on the project: Although a work schedule that balances the timing and sequenc- adding more people to the job can shorten the sched- ing of land disturbance activities (e.g., earthwork) and ule, there is a point of diminishing returns. Having the installation of erosion and sedimentation control too many people only creates a management and (ESC) measures. The objective of construction P P I * w w w. p p i 2 p a s s. c o m  P R O J E C T M A N A G E M E N T , B U D G E T I N G , A N D S C H E D U L I N G 86-9 sequencing is to reduce on-site erosion and off-site sedi- increase as a project’s completion time is decreased, mentation that might affect the water quality of nearby since more resources need to be allocated to increase water bodies. the pace. The project manager should confirm that the general Indirect costs, also known as fixed costs, are costs that construction schedule and the construction sequencing are not directly related to a particular function or prod- schedule are compatible. Key construction activities and uct. Indirect costs include taxes, administration, person- associated ESC measures are listed in Table 86.4. nel, and security costs. Such costs tend to be relatively steady over the life of the project and decrease as the Table 86.4 Construction Activities and ESC Measures project duration decreases. construction activity ESC measures The time required to complete a project is determined designate site access Stabilize exposed areas with gravel by the critical path, so to compress (or “crash”) a project and/or temporary vegetation. schedule (accelerate the project activities in order to Immediately apply stabilization to complete the project sooner), a project manager must areas exposed throughout site focus on critical path activities. development. A procedure for determining the optimal project time, protect runoff outlets Install principle sediment traps, or time-cost-trade-off, is to determine the normal com- and conveyance fences, and basins prior to grading; pletion time and direct cost for each critical path activ- systems stabilize stream banks and install ity and compare it to its respective “crash time” and storm drains, channels, etc. direct cost. The crash time is the shortest time in which an activity can be completed. If a new critical path land clearing Mark trees and buffer areas for emerges, consider this in subsequent time reductions. preservation. In this way, one can step through the critical path site grading Install additional ESC measures as activities and calculate the total direct project cost needed during grading. versus the project time. (To minimize the cost, those site stabilization Install temporary and permanent activities that are not on the critical path can be seeding, mulching, sodding, riprap, extended without increasing the project completion etc. time.) The indirect, direct, and total project costs can then be calculated for different project durations. The building construction Install additional ESC measures as optimal duration is the one with the lowest cost. This and utilities install- needed during construction. model assumes that the normal cost for an activity is ation lower than the crash cost, the time and cost are linearly landscaping and final Remove all temporary control related, and the resources needed to shorten an activity site stabilization* measures; install topsoil, trees and are available. If these assumptions are not true, then the shrubs, permanent seeding, model would need to be adapted. Other cost considera- mulching, sodding, riprap, etc.; tions include incentive payments, marketing initiatives, stabilize all open areas, including and the like. borrow and spoil areas. Fast Tracking * This is the last construction phase. Besides efficient scheduling, construction time can be compressed with fast-track scheduling. This method Time-Cost Trade-Off overlaps the design and construction phases of a project. A project’s completion time and its cost are intricately Ordering of long-lead materials and equipment can related. Though some costs are not directly related to occur, and work on the site and foundations can begin the time a project takes, many costs are. This is the before all the details of the building are completely essence of the time-cost trade-off: The cost increases as worked out. With fast-track scheduling, separate con- the project time is decreased and vice versa. A project tracts are established so that each major system can be manager’s roles include understanding the time-cost bid and awarded by itself to avoid delaying other relationship, optimizing a project’s pace for minimal construction. cost, and predicting the impact of a schedule change Although the fast-track method requires close coordina- on project cost. tion between the architect, contractor, subcontractors, owner, and others, it makes it possible to construct a and Professional The costs associated with a project can be classified as Systems, Mgmt, direct costs or indirect costs. The project cost is the sum high-quality building in 10% to 30% less time than with of the direct and indirect costs. a conventional construction contract. Direct costs, also known as variable costs, operating Schedule Management costs, prime costs, and on costs, are costs that vary directly with the level of output (e.g., labor, fuel, power, Several methods are used to schedule and monitor pro- and the cost of raw material). Generally, direct costs jects. The most common and easiest is the bar chart or P P I * w w w. p p i 2 p a s s. c o m  86-10 C I V I L E N G I N E E R I N G R E F E R E N C E M A N U A L Gantt chart, such as Fig. 86.3. The various activities of available). Usually, people and equipment are the limited the schedule are listed along the vertical axis. Each resources, although project funding may also be limited if activity is given a starting and finishing date, and over- it becomes available in stages. Two common ways are laps are indicated by drawing the bars for each activity used to level resources: (1) Tasks can be delayed (either so that they overlap. Bar charts are simple to make and by postponing their start dates or extending their com- understand and are suitable for small to midsize pro- pletion dates) until resources become available. (2) Tasks jects. However, they cannot show all the sequences and can be split so that the parts are completed when planned dependencies of one activity on another. and the remainders are completed when resources becomes available. The methods used depend on the Critical path techniques are used to graphically repre- limitations of the project, including budget, resource sent the multiple relationships between stages in a com- availability, finish date, and the amount of flexibility plicated project. The graphical network shows the available for scheduling tasks. If resource leveling is used precedence relationships between the various activities. with tasks on a project’s critical path, the project’s com- The graphical network can be used to control and moni- pletion date will inevitably be extended. tor the progress, cost, and resources of a project. A critical path technique will also identify the most critical Example 86.2 activities in the project. Because of a shortage of reusable forms, a geotechnical Critical path techniques use directed graphs to represent contractor decides to build a 250 ft long concrete wall a project. These graphs are made up of arcs (arrows) in 25 ft segments. Each segment requires the following and nodes (junctions). The placement of the arcs and crews and times. nodes completely specifies the precedences of the pro- ject. Durations and precedences are usually given in a. set forms: 3 carpenters; 2 days precedence table (matrix).. pour concrete: 3 carpenters; 1 day. strip forms: 4 carpenters; 1 day 4. RESOURCE LEVELING................................................................................................................................. The contractor has budgeted for only three carpenters. Compared to the ideal schedule, how many additional Resource leveling is used to address overallocation (i.e., days will it take to construct the wall if the number of situations that demand more resources than are