What Is Construction Site Management?
- Managing the design and construction of a stated project to achieve an architectural and construction program at the lowest beneficial cost to owner within reasonable profit framework for the participants.
- The basic function of managing the design and construction process as currently constituted is the integration of various independent factions through planning organizing and controlling
- Management function is an agency of the owner may be performed by owner ,delegated to the contractor ,the architect or an independent party ,or some combination thereof
- Construction management is more than just procedure it is a process that generates a facility at the lowest reasonable cost
- The success of the construction management will be achieved through planning, organizing and controlling thus the construction manager must comprehend contemporary techniques of management
- An ability to organize the efforts of all participant to maintain control of the contract interface, to expedite progress and to quickly reach rational decisions required
- The construction manager is an agent of the owner , an association with legal and operational consequences that affect construction management practice .legally ,an agent agrees to subordinate authority to serve the interest of client
- Group of management activities over and above normal architectural and engineering services related to a construction program ,carried out during design and construction phases ,that contributes to the control of time and cost in a new facility
- Construction management is more the bringing together of many proven management techniques than it is the development of something entirely new
- In general terms it is the application of available construction knowledge and management technique applied by a firm acting as the owner agent to project plan /design/build/occupy/process
Why It Exists?
The need to combat inflation was a major contributing factor in the rise if construction management. Before construction management was considered separate field ,time and cost control was shared by the design professional and the contractor .the contractor kept a schedule and designer kept a record of cost .this system prove beneficial until about fifteen years ago when inflation become a major concern .construction management has been able to counteract the effect of progressively rising construction cost by reducing the time required between the identification of need for a facility and occupancy. Streamlining procedure both in terms of reaching decision and of processing information, fast tracking or early bidding of critical construction contract using performance specification while details are being designed and restricting the extent and time for owner reviews are used to compress the conceive / design / period/ build
Better project control:
One of the reason for the rise of construction management is better project control and often, and owner must rely on knowledgeable and experienced organization for specialized constructed based decision. However the ability to make this decision is meaningless unless the decision maker can also implement properly. Consequently, the leaders of such an organization must adeptly manage the staff that issues decision and processes the documents that directs the work. Centralized authority should improve decision making by placing responsibility at the level where all factors that affect the total project can be considered and evaluated according to their relative contribution to the successful completion of project. Thus, better control systems from the organization a construction manager provides.
Use of sophisticated management techniques:
Better project control is closely related to sophisticated management and construction related techniques. Standard management related techniques include decision trees, risk adjusted utility analysis, and game theory; construction related techniques involve accelerated construction, value engineering, critical path schedules, life cost analysis, and range estimating.
These tools are the methods used to effectively implement construction management, and they can be considered an end as well, since society will gain from more efficient buildings constructed at lower costs and in less time.
Construction knowledge during design:
Construction management also hopes to forestall potential problems by introducing practical construction knowledge in the early phases of design. Traditionally, design professionals are artists with little knowledge of actual construction practices.They often include details in the contract documents that are not logical to construct or do not achieve the desired aesthetic result. Since the contract documents specifically define constructed methods and imply assembly techniques, the owner would be paying for the product that was not only more expensive but less suitable than needed. The application of construction understanding during the early phases of project design helps to improve design efficiency.
Control of costs:
Improved control of construction costs during design is another factor. Traditionally designers would generate bid documents without detailed, accurate cost information. If the bids received were too high, either the owner increased the budget, often using his or her contingency to do so, or the project had to be redesigned.
Recently, pressure to adhere to an owner’s budget has required that design professionals include statements of probable construction costs at various phases of their basic services.
However the design professional does not guarantee construction costs and maintain, in reserve the ability to alter the project scope so that it will fall within 10% of probable construction costs, if the bids are excessive. If inflation were 15% an 8 month delay to redesign a project that is 10% over the owner’s budget may require a 20% reduction in scope to keep the project feasible.
Team Effort instead of competition:
Traditionally the construction industry is disorganized, since different segments complete their work isolation from each other. When design professionals prepare contract documents before they are presented to the contractor for pricing, they do not get the benefit of that team member’s input. Since ambiguities and conflicts do occur, the general conditions of the contract documents usually provide a “grandfather clause” that requires contractors and sub contractors to immediately point out problems and discrepancies to design professional for interpretation and clarification. Occasionally there are penalties; more often they are not. In any case owner loses.
Construction management aims to coordinate the actions of the two into a team effort and thereby reduce conflicts and ambiguities that cannot be readily resolved.
Any site or project will have objectives in these spheres;
- Time completion is required within a certain time.
- Costs expected project costs versus benefits will enable rewards or profits to be made.
- Quality completion is required within criteria which measure standards achieved against standards required or specified.
- Performance project performance is required to satisfy the time, cost and quality parameters
These are no necessarily presented in order of importance for every project but do reflect, nevertheless the natural order:
If you do not have the time, you will not
If you do not have the money, you cannot
If you do not know what you want, you will never get it.
Take time first. Probably you have heard of plans and planning you may even prepared or taken part in some. So what is the mystery element or elements which distinguish successful plan works. The only true answer is that the successful plan works. The likely explanation is that the plan is recognized as being one of the main factors for success the others being both derived from and included in the plan and covering, perhaps the allocation and effective use of resources, cost control and the means for achieving the agreed standards.
The cost next- everybody knows what money is and what can be done with it. In project considerations, though, the focus is on particular aspects of the use of money and you will deliberately plan and to get something for a certain price you negotiate each step of the way. The cost aspect is thus broken down into three project areas:
Preparing an estimate obviously takes both time and money. The results depend upon these factors as well as the skill and experience of the estimations and the brief to which they work
Project accounting is essentially the book keeping exercise. It records expenditures into predetermined account codes and classifies them into categories such as capital funds, indirect/ direct overheads, materials, field labour, plant, etc
Project cost control on the other hand is the dynamic aspect of the project cost arena,\. Essentially it combines the estimate of time and money together with the accounting record for the expressed purpose of control, i.e. asking action.
Project cost must be achieved comprehensively and include the cost of designing, delivering, constructing, and furnishing the project.
In an inexpensive project the lead time between the preliminary design and the final working drawings is normally several weeks or months. Consequently the potential cost savings to the owner, of employing either accelerated delivery or sophisticated coordination techniques, is relatively small. The contractor can usually complete such projects with relative ease within the time span required to prepare the necessary contract documents.
If the project is more costly and, accordingly, more time is required to adequately document the design, then the techniques of construction management begin to make sense. For a more expensive project, the cost of construction management services will be offset by the overall savings gained from finishing the project sooner. Hence, services that coordinate, expedite, and improve the quality of a project should be seriously considered.
If a project is relatively simple, with a high degree of duplication, the project need not be accelerated, even if it is large or expensive. Because there is substantial duplication and standardization of components, contract documents can be completed and coordinated in relatively short time and then bid as an entire package. This would give the owner the benefit of receiving firm prices for all of the work prior to any construction.
As project complexity increases, better planned and coordinated documents are necessary if the bids are to accurately reflect the work required and if the construction is to have few problems. Such coordination will necessitate increased design time, and consequently, project expediting techniques become feasible. However complexity does not preclude the use of construction management to organize the construction of different facilities within the project
In short, increased complexity lends itself to the adoption of project expediting processes. If a project is complex, increased coordination of design, detail, and construction will be required. Such coordination extends the project time; construction management will reduce it. Consequently, construction management should be considered to improve the project schedule, delivery, and cost.
When a project is large, it can be divided into separate and distinct sub projects. For example, a new college campus will often contain specialized academic buildings, all of which are required in a basic educational program.
By adopting construction management procedures, critical buildings are identified and scheduled for expedited completion so that the entire campus is completed at the earliest date.
If separate sub projects are identified and work within each is divided into separate contracts, there is greater possibility that coordination problems will occur at the interface. The construction manager must coordinate each separate sub project and tenant work within each segment of the overall project construction. Consequently if facility is large and complex, the construction manager must attend and help coordinate each contract interface. He must not establish intervening contracts that would interfere with each contractor’s performance. Certainly all sub contracts are related to each other ; each is necessary to complete the work. However once a sub contract begins, there should be no intervening sub contracts that would prevents its completion. Nevertheless, a separate contract should never be allowed to intervene between the fabrication and installation of any single contract without giving each contractor the right to bid and perform those contracts that affect the work and profit.
In every contract, time is of the essence. In construction, control of time is critical. If the duration of a project is relatively long, there is a greater opportunity to apply construction management methods to gain efficiency and reduce time.
Every project participant has the incentive to reduce time. When the contractor’s price is fixed, reducing duration will increase his profit. The same incentive is true for the design professional who works for a lump sum or a percentage of the construction costs.
When the design and construction of a project are expected to be lengthy, the overall cost and project duration can be reduced, provided the project team maintains an expedited project schedule. Unless the owner’s chain of command and delegation of responsibility are clear, the project decision processes will take considerable time, increase the cost, and extend the project’s completion.
The construction manager should evaluate, during the preliminary design process, the dedication of the owner and the owner’s staff to the principle of reaching a fast, but not hasty, decision before any phase of the project goes into construction
Some owners can more readily utilize construction management services than others, especially if they need the construction of facilities as part of their normal business.
This experience often eliminates many of the problems and decisions that may occur during the design sequence. The same is true for government and publicly regulated agencies that provides a standard service in each of their geographically dispersed facilities.
The experience of the owner’s staff is also a factor that contributes to expediting project processes. When the owner realizes the importance of making decisions based on practical knowledge and understands that delays are costly, the project will advance.
However one important note of caution: construction management organizations are often hired by communities to provide consultant management services for a specific large scale venture. The construction management must establish communication channels with existing public departments that maintain base data information. Often the construction management organizations structure will not correspond with the bureaucratic organization of the public department. Yet there must be communication among all levels of both organizations.
This will facilitate communication between the two interdependent bodies and bypass the long line of communication involved in upward referral.
When construction management is enlisted to benefit the delivery of a project, critical decisions must be made regarding the packaging, phasing, and bidding of the construction work. Publicly funded projects require open bidding, with no contractor pre qualification. Many private owners will also want the benefit of open, competitive bidding, but often with the pre qualification of the contractor. Two construction management approaches to project assembly have resulted from this bid requirement.
DESIGN ASSEMBLED APPROACH:
The design assembled approach divides the work according to design and documentation phases, with no pre established contractor/construction manager. The design professional divides the work into packages based on construction documentation. As previously discussed, general work will begin after the general design is complete. Hence, each package covers a different phase of the work. A separate general contractor will take complete responsibility for each package and will procure bids from subcontractors needed to help complete this phase. One possible drawback of this delivery method is that the owner cannot look to a sole contracting entity to take overall responsibility for the project’s construction effort. The design professional will, have to coordinate the bid packages and evaluate each contractors responsibilities at the contract interface.
In the design assembled approach, the design professional, in effect becomes the construction manager, and the owner will look to that individual to carry out this coordination. The design professional must not only make certain that all work is covered in documents, but must also designate in which phase the installation is required.
In any case, issues such as these must be resolved by the professional and all decisions accurately reflected in the documents of the design assembled approach. The engineering and cost benefit evaluations for each alternative must be made concurrently with the concurrently with the decision on the overall approach to project delivery. These evaluations techniques will be discussed later.
SEGREGATED CONTRACT APPROACH:
The segregated contract approach divides the work according to established construction subcontract divisions. The segregated contract manager usually has a contracting background. This individual is selected on the basis of merit, not necessarily on the lowest price. During the planning stage he/she can advise without acting in conflict of interest, even though he/she may eventually participate in a subsequent construction phase, if no bid for a portion of the work is received or if the lowest bid is too high.
With this type of assembly, the segregated contract manager will oversee the work of those who would normally be subcontractors and material suppliers in conventional delivery. However, because of the requirements of public bidding, these usual subcontractors will compete with others within their specialty trade for a separate contract direct with the owner. Each segregated contractor will perform specialty work to the requirements of the design professional’s documents and in accordance with the schedule established by the segregated contract manager.
There are advantages to the segregated contract approach. This industry based method of assembling the work does allow accelerated delivery. The owner receives the direct bid from each segregated contractor without a general contractor’s handling
fee and markup. In this type of delivery the owner usually pays the segregated contract manager a fixes fee for basic services and reimburses the contract manager for variable costs, which include jobsite expense. This means that all parameters of costs are out in the open, except for unforeseen document clarifications, changes, or extraordinary expenses, all of which are covered in the owner’s contingency fund. Because of such objectivity and its reputation for minimizing costs, this approach is often applied.
Stages Of Activities:
The stages of activities representing any time of work is given below
Clear site: necessary before any survey work can start.
Survey and layout: cannot start before the site is cleared; otherwise, many of the survey stakes would be lost in the clearing operation.
Rough grade: cannot start until the area has been laid out. This activity ties up the whole site with earth moving equipment.
Drill well: cannot start until the rough grading operation’s completed
Drive and pour piles: after layout, this is the first step in the plant and warehouse
Excavate: follows piling. This is fine grading to finish grade
Spread footing: can be placed after the excavation is done.
Form and pour grade beams: are poured on top of spread footings.
Backfill and compact: is done after the grade beams are finished.
Form and pour slabs: can be done after he under slab preparations are complete.
Erect structural steel: follows the completion of foundations.
Masonry partitions: start as soon as building is closed in
Ceiling works: is supported as soon as building is closed in.
Exterior doors: can be hung after the building is closed in but must be installed prior to the dry wall.
Hand interior doors: can follow dry wall installation
Ceramic tile: can follow dry wall
Floor tile: should be held off until room painting is complete
Insulate heating and ventilating ducts: cannot be done until ductwork is in place
Fabricate piping system: can be done after the building is closed in.
Erect roof: naturally must follow the erection of the structure. Since it uses the same crane rising, it follows closely.
Exterior masonry: follows the roof erection
Paint exterior: starts after the roofing is on and doors are installed.
The control phase of a project is continually measuring and controlling
all variances throughout all phases of a project life cycle..
An accurate snapshot of the actual project (where it is) and with the
planned status (where it is supposed to be) must be made at regular
intervals, as this is the only way to control a project.
The aim of project control, in a nutshell, is to compare the actual
progress and performance against the project plan. The project manager
therefore has to analyze any variances, review possible alternatives, and
take the appropriate corrective action. Undoubtedly, project managers
need to control their projects on a regular basis; without this control
being in place, an ever-increasing level of unnecessary detail will appear.
The prime role during this phase is to
(a) Identify all symptoms or factors that would jeopardize the
(b) Outline the process for bringing the project back on track.
Controlling can be done using a basic, three-step process.
- Determine project status and if objectives are being met.
- Compare the status against project planning.
- Assess the cause of problems and implement corrective actions.
The Cost Control System
During the execution of a project, procedures for project control and record keeping become indispensable tools to managers and other participants in the construction process. These tools serve the dual purpose of recording the financial transactions that occur as well as giving managers an indication of the progress and problems associated with a project. The problems of project control are aptly summed up in an old definition of a project as "any collection of vaguely related activities that are ninety percent complete, over budget and late." The task of project control systems is to give a fair indication of the existence and the extent of such problems
The limited objective of project control deserves emphasis. Project control procedures are primarily intended to identify deviations from the project plan rather than to suggest possible areas for cost savings. This characteristic reflects the advanced stage at which project control becomes important. The time at which major cost savings can be achieved is during planning and design for the project. During the actual construction, changes are likely to delay the project and lead to inordinate cost increases. As a result, the focus of project control is on fulfilling the original design plans or indicating deviations from these plans, rather than on searching for significant improvements and cost savings. It is only when a rescue operation is required that major changes will normally occur in the construction plan.
Finally, the issues associated with integration of information will require some discussion. Project management activities and functional concerns are intimately linked, yet the techniques used in many instances do not facilitate comprehensive or integrated consideration of project activities. For example, schedule information and cost accounts are usually kept separately. As a result, project managers themselves must synthesize a comprehensive view from the different reports on the project plus their own field observations. In particular, managers are often forced to infer the cost impacts of schedule changes, rather than being provided with aids for this process. Communication or integration of various types of information can serve a number of useful purposes, although it does require special attention in the establishment of project control procedures.
The Project Budget
For cost control on a project, the construction plan and the associated cash flow estimates can provide the baseline reference for subsequent project monitoring and control. For schedules, progress on individual activities and the achievement of milestone completions can be compared with the project schedule to monitor the progress of activities. Contract and job specifications provide the criteria by which to assess and assure the required quality of construction. The final or detailed cost estimate provides a baseline for the assessment of financial performance during the project. To the extent that costs are within the detailed cost estimate, then the project is thought to be under financial control. Overruns in particular cost categories signal the possibility of problems and give an indication of exactly what problems are being encountered. Expense oriented construction planning and control focuses upon the categories included in the final cost estimation. This focus is particular relevant for projects with few activities and considerable repetition such as grading and paving roadways.
For control and monitoring purposes, the original detailed cost estimate is typically converted to a project budget, and the project budget is used subsequently as a guide for management. Specific items in the detailed cost estimate become job cost elements. Expenses incurred during the course of a project are recorded in specific job cost accounts to be compared with the original cost estimates in each category. Thus, individual job cost accounts generally represent the basic unit for cost control. Alternatively, job cost accounts may be disaggregated or divided into work elements which are related both to particular scheduled activities and to particular cost accounts. Work element divisions will be described in Section 12.8.
In addition to cost amounts, information on material quantities and labor inputs within each job account is also typically retained in the project budget. With this information, actual materials usage and labor employed can be compared to the expected requirements. As a result, cost overruns or savings on particular items can be identified as due to changes in unit prices, labor productivity or in the amount of material consumed.
Controlling the Site Schedule
Construction typically involves a deadline for work completion, so contractual agreements will force attention to schedules. More generally, delays in construction represent additional costs due to late facility occupancy or other factors. Just as costs incurred are compared to budgeted costs, actual activity durations may be compared to expected durations. In this process, forecasting the time to complete particular activities may be required. There are several ways to update the schedule. The most frequently used methods are percent completed, remaining duration, duration completed, estimated completion date, and actual start and actual finish dates. The goal is to provide enough information to compare accurately the present project status to the planned target. Any delay in project implementation places the project at risk of possibly being overtaken by technological change. If this is the case, it is vital that project plans are flexible enough to allow for the insertion of newer technologies when they are released.
Some of the schedule issues that need to be controlled are
•Erroneous activity sequencing (incorrect WBS)
•Project tasks being incorrect because the quantities of resources are unavailable.
•Changing requirements (which always require additional rework
•Incorrect or unrealistic activity duration estimates
Control of Project Cash Flows
These components include costs incurred (as described above), billings and receipts for billings to owners (for contractors), payable amounts to suppliers and contractors, financing plan cash flows (for bonds or other financial instruments), etc
The job status reports illustrated in this and the previous sections provide a primary tool for project cost control. Different reports with varying amounts of detail and item reports would be prepared for different individuals involved in a project. Reports to upper management would be summaries, reports to particular staff individuals would emphasize their responsibilities (Eg. purchasing, payroll, etc.), and detailed reports would be provided to the individual project managers. Coupled with scheduling reports described in Chapter 10, these reports provide a snapshot view of how a project is doing. Of course, these schedule and cost reports would have to be tempered by the actual accomplishments and problems occurring in the field. For example, if work already completed is of sub-standard quality, these reports would not reveal such a problem. Even though the reports indicated a project on time and on budget, the possibility of re-work or inadequate facility performance due to quality problems would quickly reverse that rosy situation.
Schedule and Budget Updates
Scheduling and project planning is an activity that continues throughout the lifetime of a project. As changes or discrepancies between the plan and the realization occur, the project schedule and cost estimates should be modified and new schedules devised. Too often, the schedule is devised once by a planner in the central office, and then revisions or modifications are done incompletely or only sporadically. The result is the lack of effective project monitoring and the possibility of eventual chaos on the project site.
On "fast track" projects, initial construction activities are begun even before the facility design is finalized. In this case, special attention must be placed on the coordinated scheduling of design and construction activities. Even in projects for which the design is finalized before construction begins, change orders representing changes in the "final" design are often issued to incorporate changes desired by the owner.
Periodic updating of future activity durations and budgets is especially important to avoid excessive optimism in projects experiencing problems. If one type of activity experiences delays on a project, then related activities are also likely to be delayed unless managerial changes are made. Construction projects normally involve numerous activities which are closely related due to the use of similar materials, equipment, workers or site characteristics. Expected cost changes should also be propagated thoughout a project plan. In essence, duration and cost estimates for future activities should be revised in light of the actual experience on the job. Without this updating, project schedules slip more and more as time progresses. To perform this type of updating, project managers need access to original estimates and estimating assumptions.
Unfortunately, most project cost control and scheduling systems do not provide many aids for such updating. What is required is a means of identifying discrepancies, diagnosing the cause, forecasting the effect, and propagating this effect to all related activities. While these steps can be undertaken manually, computers aids to support interactive updating or even automatic updating would be helpful.
Beyond the direct updating of activity durations and cost estimates, project managers should have mechanisms available for evaluating any type of schedule change. Updating activity duration estimations, changing scheduled start times, modifying the estimates of resources required for each activity, and even changing the project network logic (by inserting new activities or other changes) should all be easily accomplished. In effect, scheduling aids should be directly available to project managers
Controlling Project Resources
The responsibility of managing the correct quantity of resources on a
project is demanding. Project managers must ensure that sufficient
resources are used on all project activities that were planned earlier
during the project-planning phase. In many situations, there are either
too little or too many staff members performing these tasks, and it
becomes the responsibility of the project manager to level these
resources out and to maintain the right amount of resources on the task.
It doesn't make any financial sense to keep additional resources on the
project if they won't be used again.
So, these members will likely have to
be released. If the resources have specialist skills that are considered
crucial to the client, then the necessary arrangements must be made to
retain those resources.
If, however, if too few resources working on an important task that has to be completed within a certain date, then there are a few options available
•Add additional staff members from other tasks to the important
task, hoping to reduce the duration.
•Hire additional resources just for the task duration.
Controlling Project Costs:
The project manager must capture, track, and control all project-related
costs that are incurred against planned project cost items. Whether it is
project timesheets, hardware, or travel expenses, it is essential that all
costs be reflected against the project. This provides a realistic measure of
what the project cost the company at the end of the day. Additionally, it
also helps measure how well the project was planned.
It is necessary that these costs be captured on the project system that
the project manager is using. In the event where unforeseen costs arise,
it is the project manager's responsibility to immediately compare the cost
item (invoice) against the planned project cost WBS task. If there is a
difference, it implies a loss on the specific WBS work package, not
necessarily on the total project. If the tendency is similar on many of the
WBS tasks, then it is probable that the project will be heading for a loss,
indicating bad planning and estimation. There is nothing that the project
manager is able to do. To aid the project managers in cost control, the
following items need to be verified:
•The budget allocations are accurate and correct.
•The original project estimate and budget are correct.
•The original prices used to develop the estimate still apply and
•Technical difficulties will affect the cost of the project.
However, when costs are incurred against the project and it is found that
an actual cost item is slightly higher than the planned WBS cost, , for the project must remain profitable to the company, no more additional cost overruns can be tolerated. The costs must now be controlled even more than ever. Remember, depending on the contract value, the overall project will not immediately reflect this loss; initially only single WBS items reflect this loss.
Organizing for Quality and Safety
A variety of different organizations are possible for quality and safety control during construction. One common model is to have a group responsible for quality assurance and another group primarily responsible for safety within an organization. In large organizations, departments dedicated to quality assurance and to safety might assign specific individuals to assume responsibility for these functions on particular projects. For smaller projects, the project manager or an assistant might assume these and other responsibilities. In either case, insuring safe and quality construction is a concern of the project manager in overall charge of the project in addition to the concerns of personnel, cost, time and other management issues.
Inspectors and quality assurance personnel will be involved in a project to represent a variety of different organizations. Each of the parties directly concerned with the project may have their own quality and safety inspectors, including the owner, the engineer/architect, and the various constructor firms. These inspectors may be contractors from specialized quality assurance organizations. In addition to on-site inspections, samples of materials will commonly be tested by specialized laboratories to insure compliance. Inspectors to insure compliance with regulatory requirements will also be involved. Common examples are inspectors for the local government's building department, for environmental agencies, and for occupational health and safety agencies.
The US Occupational Safety and Health Administration (OSHA) routinely conducts site visits of work places in conjunction with approved state inspection agencies. OSHA inspectors are required by law to issue citations for all standard violations observed. Safety standards prescribe a variety of mechanical safeguards and procedures; for example, ladder safety is covered by over 140 regulations. In cases of extreme non-compliance with standards, OSHA inspectors can stop work on a project. However, only a small fraction of construction sites are visited by OSHA inspectors and most construction site accidents are not caused by violations of existing standards. As a result, safety is largely the responsibility of the managers on site rather than that of public inspectors.
While the multitude of participants involved in the construction process require the services of inspectors, it cannot be emphasized too strongly that inspectors are only a formal check on quality control. Quality control should be a primary objective for all the members of a project team. Managers should take responsibility for maintaining and improving quality control. Employee participation in quality control should be sought and rewarded, including the introduction of new ideas. Most important of all, quality improvement can serve as a catalyst for improved productivity. By suggesting new work methods, by avoiding rework, and by avoiding long term problems, good quality control can pay for itself. Owners should promote good quality control and seek out contractors who maintain such standards.
In addition to the various organizational bodies involved in quality control, issues of quality control arise in virtually all the functional areas of construction activities. For example, insuring accurate and useful information is an important part of maintaining quality performance. Other aspects of quality control include document control (including changes during the construction process), procurement, field inspection and testing, and final checkout of the facility.
Work and Material Specifications
Specifications of work quality are an important feature of facility designs. Specifications of required quality and components represent part of the necessary documentation to describe a facility. Typically, this documentation includes any special provisions of the facility design as well as references to generally accepted specifications to be used during construction.
General specifications of work quality are available in numerous fields and are issued in publications of organizations such as the American Society for Testing and Materials (ASTM), the American National Standards Institute (ANSI), or the Construction Specifications Institute (CSI). Distinct specifications are formalized for particular types of construction activities, such as welding standards issued by the American Welding Society, or for particular facility types, such as the Standard Specifications for Highway Bridges issued by the American Association of State Highway and Transportation Officials.
These general specifications must be modified to reflect local conditions, policies, available materials, local regulations and other special circumstances. Construction specifications normally consist of a series of instructions or prohibitions for specific operations. For example, the following passage illustrates a typical specification, in this case for excavation for structures:
Conform to elevations and dimensions shown on plan within a tolerance of plus or minus 0.10 foot, and extending a sufficient distance from footings and foundations to permit placing and removal of concrete formwork, installation of services, other construction, and for inspection. In excavating for footings and foundations, take care not to disturb bottom of excavation. Excavate by hand to final grade just before concrete reinforcement is placed. Trim bottoms to required lines and grades to leave solid base to receive concrete.
This set of specifications requires judgment in application since some items are not precisely specified. For example, excavation must extend a "sufficient" distance to permit inspection and other activities. Obviously, the term "sufficient" in this case may be subject to varying interpretations. In contrast, a specification that tolerances are within plus or minus a tenth of a foot is subject to direct measurement. However, specific requirements of the facility or characteristics of the site may make the standard tolerance of a tenth of a foot inappropriate. Writing specifications typically requires a trade-off between assuming reasonable behavior on the part of all the parties concerned in interpreting words such as "sufficient" versus the effort and possible inaccuracy in pre-specifying all operations.
In recent years, performance specifications have been developed for many construction operations. Rather than specifying the required construction process, these specifications refer to the required performance or quality of the finished facility. The exact method by which this performance is obtained is left to the construction contractor. For example, traditional specifications for asphalt pavement specified the composition of the asphalt material, the asphalt temperature during paving, and compacting procedures. In contrast, a performance specification for asphalt would detail the desired performance of the pavement with respect to impermeability, strength, etc. How the desired performance level was attained would be up to the paving contractor. In some cases, the payment for asphalt paving might increase with better quality of asphalt beyond some minimum level of performance.
Total Quality Control
Quality control in construction typically involves insuring compliance with minimum standards of material and workmanship in order to insure the performance of the facility according to the design. These minimum standards are contained in the specifications described in the previous section. For the purpose of insuring compliance, random samples and statistical methods are commonly used as the basis for accepting or rejecting work completed and batches of materials. Rejection of a batch is based on non-conformance or violation of the relevant design specifications. Procedures for this quality control practice are described in the following sections.
An implicit assumption in these traditional quality control practices is the notion of an acceptable quality level which is a allowable fraction of defective items. Materials obtained from suppliers or work performed by an organization is inspected and passed as acceptable if the estimated defective percentage is within the acceptable quality level. Problems with materials or goods are corrected after delivery of the product.
In contrast to this traditional approach of quality control is the goal of total quality control. In this system, no defective items are allowed anywhere in the construction process. While the zero defects goal can never be permanently obtained, it provides a goal so that an organization is never satisfied with its quality control program even if defects are reduced by substantial amounts year after year. This concept and approach to quality control was first developed in manufacturing firms in
Japan and Europe, but has since spread to many construction companies. The best known formal certification for quality improvement is the International Organization for Standardization's ISO 9000 standard. ISO 9000 emphasizes good documentation, quality goals and a series of cycles of planning, implementation and review.
Total quality control is a commitment to quality expressed in all parts of an organization and typically involves many elements. Design reviews to insure safe and effective construction procedures are a major element. Other elements include extensive training for personnel, shifting the responsibility for detecting defects from quality control inspectors to workers, and continually maintaining equipment.
Worker involvement in improved quality control is often formalized in quality circles in which groups of workers meet regularly to make suggestions for quality improvement. Material suppliers are also required to insure zero defects in delivered goods. Initally, all materials from a supplier are inspected and batches of goods with any defective items are returned. Suppliers with good records can be certified and not subject to complete inspection subsequently.
The traditional microeconomic view of quality control is that there is an "optimum" proportion of defective items. Trying to achieve greater quality than this optimum would substantially increase costs of inspection and reduce worker productivity. However, many companies have found that commitment to total quality control has substantial economic benefits that had been unappreciated in traditional approaches. Expenses associated with inventory, rework, scrap and warranties were reduced. Worker enthusiasm and commitment improved. Customers often appreciated higher quality work and would pay a premium for good quality. As a result, improved quality control became a competitive advantage. Of course, total quality control is difficult to apply, particular in construction. The unique nature of each facility, the variability in the workforce, the multitude of subcontractors and the cost of making necessary investments in education and procedures make programs of total quality control in construction difficult. Nevertheless, a commitment to improved quality even without endorsing the goal of zero defects can pay real dividends to organizations.
Risk control is the process of continually assessing the condition of the
project and developing options to permit alternative solutions
Project managers should take care to identify consequences that are
likely to occur and any indicators of the start of the problem.
The following are some suggestions for risk control:
•Continually update the risk management plan.
•Implement risk avoidance actions.
•Implement risk contingency actions.
•Report on each risk issue.
•Monitor and analyze the effectiveness.
Various measures are available to improve jobsite safety in construction. Several of the most important occur before construction is undertaken. These include design, choice of technology and education. By altering facility designs, particular structures can be safer or more hazardous to construct. For example, parapets can be designed to appropriate heights for construction worker safety, rather than the minimum height required by building codes.
Choice of technology can also be critical in determining the safety of a jobsite. Safeguards built into machinery can notify operators of problems or prevent injuries. For example, simple switches can prevent equipment from being operating when protective shields are not in place. With the availability of on-board electronics (including computer chips) and sensors, the possibilities for sophisticated machine controllers and monitors has greatly expanded for construction equipment and tools. Materials and work process choices also influence the safety of construction. For example, substitution of alternative materials for asbestos can reduce or eliminate the prospects of long term illnesses such as asbestiosis.
Educating workers and managers in proper procedures and hazards can have a direct impact on jobsite safety. The realization of the large costs involved in construction injuries and illnesses provides a considerable motivation for awareness and education. Regular safety inspections and safety meetings have become standard practices on most job sites.
Pre-qualification of contractors and sub-contractors with regard to safety is another important avenue for safety improvement. If contractors are only invited to bid or enter negotiations if they have an acceptable record of safety (as well as quality performance), then a direct incentive is provided to insure adequate safety on the part of contractors.
During the construction process itself, the most important safety related measures are to insure vigilance and cooperation on the part of managers, inspectors and workers. Vigilance involves considering the risks of different working practices. In also involves maintaining temporary physical safeguards such as barricades, braces, guy lines, railings, toe boards and the like.
Sets of standard practices are also important, such as
- Requiring hard hats on site.
- Requiring eye protection on site.
- Requiring hearing protection near loud equipment.
- Insuring safety shoes for workers.
- Providing first-aid supplies and trained personnel on site
While eliminating accidents and work related illnesses is a worthwhile goal, it will never be attained. Construction has a number of characteristics making it inherently hazardous. Large forces are involved in many operations. The jobsite is continually changing as construction proceeds. Workers do not have fixed worksites and must move around a structure under construction. The tenure of a worker on a site is short, so the worker's familiarity and the employer-employee relationship are less settled than in manufacturing settings. Despite these peculiarities and as a result of exactly these special problems, improving worksite safety is a very important project management concern
Construction management is not really a new concept; only recently has it become a dominant force in construction. It exists as a new profession in response to economic pressures and the lack of clear project leadership within the construction industry proper.
Nonetheless, construction management has succeeded where others failed. Not only, it has incorporated modern management techniques and advanced construction controls, but more importantly, it works within the framework of today’s construction industry by retaining the specialized activities of design professional and contractor under its control. Since construction management techniques can readily adopted in almost every construction venture, construction management provides a reasonable way to deliver a project that meets an owner individual preferences and specific project requirements.