原文：Assessment of cost control systemsThe most important function that facilitates construction organizations to accomplish profit maximization is cost control. However, the absence of a well established cost control system has caused failures to many Thai contractors especially during the current economic recession period. To comprehensively understand cost control systems in practice, this study theoretically assessed effectiveness as well as the deficiencies of the 'traditional' systems the 'effective' systems. In addition, by contrasting what are found in 'effective' systems but not found in 'traditional' systems, critical attributes most contributing to the systems' successfulness were identified so that the improvement steps can be suitably prioritized. The validated findings indicated remarkable contrasts between 'traditional' and 'effective' systems. Two critical aspects, including advancement of cost control framework and systematic participation of site personnel in cost control, were found to be the major differences. Interestingly, similar conditions were encountered in various countries such as Greece, Pakistan and Australia; hence suggestions from this study could be internationally useful.In actuality, contractors perceive cost control as a pre-requisite factor towards profit maximization. An unprecedented growth in the Thai construction industry since the late 1980s had rotated the market to be the contractors' in which high profit margin could be facilely accommodated in bid quotation. A roll of forthcoming projects continually offered and contracted without intermission thus allowed contractors to luxuriate in advanced payment and credit from suppliers. This healthy cash flow situation, unfortunately, could be predominant over real profit materialization. Actual symptoms of unsystematic cost control in most Thai construction companies have been concealed until apparent recessionof the economy in 1997. Severe declination of the Thai GDP and construction growth rates shown has given rise to business failures in many organizations. Equally worse, for the others surviving, extremity of nightmares in the ultimately low-demand market is still unpredictable.Cost control systemDespite extensive literatures reviewed in cost control, an integrated view of the system was not portrayed. The system functions were mostly discussed in isolated fashion, for instance, estimating budgeting, monitoring and analysing, and reporting. Furthermore, most previous research works concentrated more on theoretical concepts rather than operation in the real-complicated environment.Applying a synergetic approach, the integrated view of the cost control system is proposed to enhance value of past efforts. As a main framework, the cost control system in this paper is defined as a kind of information system that aims to provide management with timely and accurate cost information so that timely proper corrective actions can be taken. In addition, management information can be stored in a historical database and, in turn, serves as a feedback for future estimation. The system consists of three main parts, namely, cost control framework, cost control functions and management information.To solidify a specific set of objectives, a pre-survey of existing cost control systems in Thai large-scale construction organizations was primarily conducted. A contact list of the top 100 organizations in terms of turnover was achieved through collaboration with the Thai Contractors Association (TCA). Each contract ever handled by these organizations covers a project area equivalent to over 30000 or has approximate value of more than 100 million Baht (3 million $US). Introductory letters were sent to the top 100 contractors requesting assistance on the preliminary survey of their cost control systems. Telephone interviews were followed up. Two focal points regarding the recent development of cost controlsystem and the system's ability to indicate the on-going cost status of each work item were investigated.The result elaborated indicated that the cost control systems in most organizations have not been changed much from the past. Out of 100 organizations, only five have initiated a development plan and only two of them have successfully implemented their cost control systems. Based upon this finding, two types of the system can be categorized. First, the 'traditional' system, commonly found in most organizations, is the system that has never been seriously developed and implemented. Secondly, the 'effective' system is the system that has been seriously and continuously improved until management information that facilitates decision making for timely and proper corrective actions as well as estimating process in future projects can be obtained. This type of system, unfortunately, is exceptionally found in a few organizations.ObjectivesTo achieve better understanding of how the existing systems in real practices are being operated and thereby formulate focal aspects for improvement, the specific objectives of this paper were to: • Conduct a compa rative assessment between 'traditional' and 'effective' cost control systems in accordance with the integrated system view including cost control framework, cost control functions and management information.• Identify critical attributes that most contrib ute to the system successfulness by contrasting what are found in 'effective' systems but not found in 'traditional' systems.MethodologyQualitative research, particularly 'case study', that persuades through rich depiction and strategic comparison across cases (Firestone, 1987), was chosen as the key methodology in this study. For cases sampling, the 'theory based' and 'typical case' strategies proposed by KUZEL (1992)and Patton (1980) was ground for selecting the cases of 'effective' and 'traditional' cost control systems, respectively. Besides, the 'multiple case' strategy (Yin, 1991) that can add confidence to findings was also applied. Because of the classified nature of cost information, most organizations, unfortunately, were reluctant to allow researchers an in-depth investigation. Two organizations that qualified as 'traditional' systems were volunteers and the two organizations that qualified as 'effective' systems were persuaded to participate in the assessment. The profiles of the sampled organizations are shown in Table 2. It should be noted that the names of the cases have been changed by randomly assigned the sequence A, B, C, D for confidentiality and unbiased analysis.Measure identification and system assessmentBased on the integrated view of the cost control system shown in, this section selectively elaborates substantial aspects and essence of each component, thereby identifying measures that enable system evaluation. To maintain continuity, comparative discussion of the assessed results among the four cases is also presented. This section consists of two main parts including (1) cost control framework, and (2) cost control functions and management information.Cost control frameworkThis part consists of three substantial factors, namely Work Breakdown Structure (WBS), Cost Code and Earned Value Concept. The essence of these factors was widely discussed by many researchers. It is well accepted that these factors must be appropriately employed as a critical frame for cost control system. With well-established framework, management can systematically manage the project in small manageable fashion and will not be overwhelmed by information explosion during construction phase. A pattern of proper cost control framework is illustratedWork breakdown structureA task-oriented family tree of activities widely known as WBS is indispensable for project cost control. Unemployment or improper design of this structure can cause a chain of deficiencies in all cost control functions. Commencing with estimating and budgeting, work items may be duplicated, overlooked, or shelter inadequate details. This ineffective control reference, therefore, cannot be served as a guideline for systematic monitoring as well as comprehensive analysing. Finally, an evaluation of project outcome and establishment of historical cost data can also be ineffective.Systematic structureThe project must be partitioned into manageable elements of work for which budgets and expenditures can be systematically controlled. Formation of the WBS must begin by subdividing, or partitioning the project objective into successively smaller work elements until the lowest level to be reported on or controlled is reached.Compliance with accounting codeWhen an accounting system is integrated within the cost control system, not only data processing can be substantially speeded up but also many frauds can be avoided. For instance, the account payable checking system can directly verify whether invoices of each work item are still under-budget and should be paid or not. Furthermore, account reports generated at head office and job cost reports generated at site can be crosschecked for ensuring accuracy.Cost statusIf the company employs the earned value concept, cost status at a given progress can be identified. The cost status can be defined as Cost status = earned value — total actual expenditure used to accomplish a given earned progress; when (Positive value = underrun, negative value = overrun), and Earned value = budget unit price x actual quantity in placeBy identifying the cost status, management gains an insight on whether and how much, at a given progress, the total actual expenditure of each item has been over or under the established budget. At a given progress, the cost status can be identified before the finishing of the work item so that timely proper corrective actions can be taken before being too late. Significantly, an effective report format should contain both: (1) comparison among actual quantity in place or percent progress, budget and total actual expenditure that is used to accomplish the earned progress, and (2) calculated earned value and cost status.Cost control functionsReferring to the previous part, the assessment of the control framework probably enables the author to summarize effectiveness as well as deficiencies of each audited system. However, to acquire more confidence and a richer picture, assessment of each control function has to be taken into account. Subjected to research constraints, efforts spent in this section did not try to cope with all excessive detail in real practices, yet it valuably covers all critical aspects.This part broke down into seven sub-sections consisting of one supported function estimating and six functions for cost control budgeting, monitoring, analysing, reporting, corrective action, and post-evaluating. The cost control function breakdown structure shown illustrates major components in each function.Advancement of cost control frameworkThe results indicated that control framework applied in the 'effective' system incorporated more advanced theoretical framework than the 'ineffective' system. Three critical advancements were found to be successful contributions for effective system functions. First, one integrated control frame (WBS and CBS) sheltering adequate level of detail facilitates monitoring of actual expenditures of each work item in terms of activity progress. Secondly, incorporated with application of theearned value concept, cost status can be identified before finishing of each work item, thus allowing timely and proper corrective actions. Thirdly, the integration of an accounting system within the cost control system not only substantially synchronizes on-site and head office data transferring but also ensures accuracy and consistency of the control mechanism.Systematic participation of site personnel in cost controlAnother critical difference between 'effective' and 'ineffective' systems is systematic participation of site personnel in cost control. The 'effective' system involving participation of project manager (site) in the decision for budget allocation enables in achieving a realistic budget and transferring the goals of the company to on-site management. Then, clarity of site responsibilities in monitoring, analysing and reporting the cost status do motivate site personnel to consciously exercise corrective actions on daily basis.In view of the whole system, the results of the case studies clearly showed that both organizations with 'ineffective' control framework also do not encourage the site participation programme. Practically, the head office does not let site personnel know the budget and assigns them control only in terms of quantity. For cost monitoring, analysing and reporting, the responsibility is taken by accountants who can generate information based on bills and invoices. As a result, the generated cost information cannot reflect the real on-site situation and cannot provide great benefits to management to take proper and timely corrective actions. On the other hand, the others with 'effective' control framework also have systematic participation of site personnel in cost control, which undoubtedly contributes to the goal achievement. To improve the 'ineffective' system, the first appropriate pace would fall in advancing the cost control framework. After this advancement is significantly improved, the concentration can be switched to the systematicparticipation of site personnel in cost control so that a more effective system can be achieved.Although this study has focused on cost control practices in Thailand, a developed theoretical assessment framework would be of use to the international community. In addition, common practices have been interestingly found in various countries. Earned value concept has not been applied in Greek construction organizations. Pakistani construction companies collect feedback data only through monthly cost bills. The lack of any truly site-based control system was significantly found in Australia. It is apparent that conditions in these countries are still very much near the Thai, therefore, the suggestions of this study would be widely applicable. However, to confidently generalize these findings, more case studies in different countries need to be undertaken.Source:Reinhardt,2001.“Engineering,Construction and Architectural Management.” Harvard business review”. August.pp.368-380.译文：评估成本控制系统成本控制最重要的功能是有利于施工组织完成利润最大化。