What is the theoretical and practical significance of construction cost control?

I. Historical Evolution of Cost Consultation In ancient China, many dynasties built large-scale buildings, which enabled craftsmen of past dynasties to accumulate rich architectural skills and experience. After summing up, they gradually formed the theory and method of project management and cost management, which is the embryonic form of cost consultation. From the16th century, in Britain, where capitalism developed earliest, the builders at that time began to need help to determine or estimate the labor and materials needed for a project, and to calculate and determine the solved engineering workload, so as to get due remuneration from the owners or contractors. It is this need that leads to the emergence of ——QS, a professional profession engaged in the determination and control of project cost. By the19th century, Britain began to implement the bidding system in engineering construction. In this way, formal cost specialty and specialized engineering cost management discipline were born in Britain. 1868, the Royal Institute of Chartered Surveyors -RICS was established, marking the formal birth of modern engineering cost management specialty. From 1930s to 1940s, many economic principles were applied to the field of project cost management. Foreign project cost management began to pay attention to the evaluation of investment benefit and the economic and financial analysis of the project, and created the basic theories and methods related to project cost management, such as "Engineering Economics-EE". Although the game theory appeared later than the bidding system, the perfection and innovation of the bidding system are greatly influenced by the game theory. General project cost determination and simple project cost control belong to the initial stage of cost consultation, lacking technical content, and the cost consultation industry should expand to high-end business. From 1970s to 1980s, cost engineers' associations in various countries started their own qualification certification for cost engineers. ICEC was founded in 1976. In the late 1980s and early 1990s, "life cycle cost management" was put forward. Later, the concept and theory of "Total Cost Management (TCM)" involving strategic asset management and project cost management were mainly put forward by American engineering cost management scholars. Whole-process cost control refers to the whole-process cost consultation activities from project establishment to project completion, including bidding, design scheme comparison and optimization, construction process control, completion settlement audit and so on. Life-cycle cost management is a longitudinal extension of cost management activities, extending forward to project planning and feasibility study, and backward to the management of operation and maintenance stage, that is, cost management and consultation from the birth of the project to the end of the life cycle. Total cost management is a horizontal extension of cost management activities, which extends the scope of cost consultation from simple cost management of building products to bidding and purchasing of equipment, furniture and operation and maintenance. Second, the role of BIM in the whole process of cost control The role of BIM (Building Information Modeling-Building Information Modeling) in the engineering cost consulting industry has not been recognized. BIM is a revolutionary public platform in the construction industry, which plays an important role and will bring profound changes to the construction industry. To realize the whole process cost control, whole life cycle and comprehensive cost management, BIM can't be absent. BIM is the technical support of the whole process of cost control, and it is essential to some extent. BIM is characterized by multidimensional visualization, dynamic change and information sharing. BIM is defined by the American Institute of Architecture as the digital expression and shareable knowledge resource of a building project, which includes both physical information and functional information of the project, in order to provide reliable basis for various decisions. Time is the whole life cycle from project concept generation to demolition. BIM technology is the correspondence and coupling with the theory of total cost management. BIM is the information carrier of virtual building. In the life cycle of a building, relevant personnel can not only load information on it, but also extract the required information at will. BIM technology provides strong technical support for total cost management, which makes BIM technology useful. BIM can provide value-added services such as simulation construction, collision detection and equipment management. For example, collision inspection can check whether there is any conflict in the layout of various pipeline equipment before construction, so as to avoid rework and various additional claims, and the contribution rate to cost control will reach about 20%. Only by sharing model information can we reduce a lot of labor costs and improve the utilization and transparency of engineering information. Three. The content of the whole process cost control The whole process control includes the necessity study, feasibility study and report preparation, economic comparison between design scheme and budget preparation, construction drawing review and budget preparation, bidding and contract signing, determination and control of the construction process cost, claim settlement at each stage, completion settlement, economic evaluation of completed investment and capital transfer of fixed assets. Combining the investment theory with the actual situation, and flexibly using professional scientific methods, we can achieve the best investment benefit on the premise of achieving the best use function of the building, so as to control the cost within the best range (3%) and avoid hidden unnecessary waste caused by various factors. Change ex post control into process control and ex post control. The earlier the cost control is involved, the better the effect will be. We can implement the whole process and all-round dynamic management of the project cost, and abandon the passive method of "compensating after the sheep dies", that is, auditing the construction drawing budget and finally settling the construction project funds to control the project cost, which can reverse the situation that the project cost is out of control, and put an end to and reduce the phenomena of "low price and inferior quality", "winning the bid at low price, claiming for compensation at high price" and "overestimating and taking risks". This is a complex, concrete and highly technical job, which needs the operation of a professional team. Four. Implementation measures of whole process cost control 1. Compile the implementation plan of the whole process cost control in the construction stage. The implementation plan is a programmatic document for cost control. According to the needs of the entrustment contract and the characteristics of the project, the implementation plan of the whole process cost control in the construction stage should be compiled, including the general situation of the project; Cost control organization; Cost control process; Consultation contents at each stage; Feasible work plan, etc. Arrange cost engineers to enter the site for consulting services in a reasonable and orderly manner. According to the characteristics of this project, the supervision department is equipped with corresponding professional cost engineers. Through the example analysis of the cost control scheme in the design stage, it shows that the influence of design on the project cost is the most important, so we should pay attention to the control in the design stage and control the design well in order to control the cost. It is necessary to implement the open bidding system for design, compete fairly, and take effective control of project cost as one of the main criteria for selecting the winning bidder for design. Most designers in our country often pay more attention to technology than economy in their design. It seems that the designer is only responsible for the quality of the design project, and doesn't care much about the level of the project cost, which leads to the high project cost or the out-of-control investment due to unreasonable design. Cost engineers should be involved in the design stage and put forward constructive suggestions on design scheme, structural system and material selection. If the shape and layout of the building are improper, it will not only increase the cost, but also weaken the seismic performance of the building. If a sketch without practical value and use function is added to the design, it may enhance the aesthetic function of the building, while others are just the opposite, affecting the aesthetic feeling of the building. If the cost is high, we should consider and suggest whether to cancel it. Perhaps cost engineers need to cultivate aesthetic knowledge and ability. The second is whether to consider using some light building materials instead of heavy building materials, which can effectively reduce the weight of buildings and thus reduce costs; We should analyze the cost of various structural systems and basic schemes, and choose the scheme with relatively low cost and safe structure. Cost engineers should know and be familiar with the knowledge of architectural design and structural design, and can use their own professional knowledge to compare and optimize design schemes from the perspective of cost. Whether the structural design is reasonable can be analyzed and judged from the indicators such as reinforcement ratio and steel content. However, the premise of any architectural design and structural design optimization is to ensure the safety and durability of the structure. If too much consideration is given to the project cost, which will affect the safety of the structure or increase the cost of future operation, maintenance and reinforcement, it will not be worth the loss, and it will not be optimal from the perspective of the whole life cycle of the project. Bidding also helps to control costs. Through public bidding, formulate reasonable and scientific bidding rules, select qualified contractors with reasonable quotation, excellent technology, standardized management and good reputation, and avoid the failure of the project due to improper selection of the winning bidder. In order to avoid the occurrence of corruption such as black-box operation, human intervention and collusion, once one of these situations occurs in bidding, bidding will completely lose its meaning and fail to achieve the purpose of cost control. 2. Strictly control the engineering change procedure. Engineering changes are inevitable. Formulate a set of perfect measurement, payment and change management methods, emphasize pre-control, strengthen in-process control and improve post-control. Improve the design change procedures and avoid frequent design changes, unless it is a corrective change, a mandatory change or a change that the owner wants. For example, the changes proposed by the construction unit must be reported, reviewed by the supervision engineer and approved by the owner before implementation. The cost of engineering change is related to the change plan. Therefore, the change project report must explain the change plan and the corresponding change price at the same time, so that the owner can know fairly well when making decisions and avoid the cost out of control. Construction units often make a fuss about design changes, especially the projects in unit price contract. Generally, the content of the integrated unit is changed through design changes, so as to achieve the purpose of changing the unit price, realize "turning losses into profits", and resolve and disperse the project risks, but it will cause unnecessary expenses to the owner. The essence of engineering change management is also the management of engineering claim. Claim generally refers to the actual loss caused by the situation that should be borne by the other party due to no fault of our own during the performance of the contract, and the desire to ask the other party to give economic compensation or time compensation. It is an act of economic compensation, not a punishment. It can be regarded as the increase or decrease of the agreed price, the contractor's claim and the owner's counterclaim. In international projects, general construction claims must reach 10% ~ 15% of the contract price, and some even more. Therefore, the prevention and settlement of claims is very important for project investment control. In the process of project implementation, the settlement of claims is related to the interests of owners and contractors. As a cost engineer, we should take the contract as the premise, take the facts as the basis, treat the vulnerable groups well, and use our own cost control level and contract management ability to solve the claim objectively and fairly. At the same time, in the process of settlement of claims, engineers should consider the relationship between cost, construction period and quality, and cannot ignore any party. We should not only safeguard the interests of both parties, but also control the project cost within a satisfactory range. There are many events and factors that cause claims, so it is necessary to distinguish primary and secondary responsibilities, check the accuracy, completeness and settlement time of engineering changes and on-site visas, and try to avoid and reduce the occurrence of claims. Such as basement drainage fees, safety protection railings and other fees belong to technical measures fees and safety construction measures fees, which are used in the total contract price and are not allowed to be calculated repeatedly in the form of visas. In actual construction, due to the rainy season construction, the number of drainage increases, which is predictable by mature contractors, and some construction parties intentionally or unintentionally want the supervisor and the owner to apply for on-site visas. 3. Go deep into the site to understand and collect relevant information in time. Cost management personnel should go deep into the site, keep abreast of the situation and collect all kinds of information that may cause cost adjustment. Attention should be paid to the accumulation of original materials, especially some hidden projects, and first-hand materials such as images, pictures and documents should be grasped in time. Don't wait until it is solved, otherwise it will lead to a passive situation of "dead men tell no tales" and chaos. 4. Strengthen the dynamic tracking and control of project cost. The construction period of a construction project is generally long, and changes in the market (such as interest rate, exchange rate, labor, materials and machinery needed in construction) and the project itself will have an impact on the project cost. In order to ensure that the whole project cost is controlled within the scope of the contract, the cost engineer will track the project cost in time and make adjustments in time according to the market and site conditions and the current situation of the expenses that have occurred and will occur. 5. Timely project settlement is the last stage of cost control. Before the settlement of the project, collect and sort out all kinds of measurement and payment data in time to ensure completeness. When the project is settled, pay attention to deduct the advance payment, warranty money, materials provided by Party A, etc. Especially for some projects that the owner can enjoy preferential policies or reduce some taxes and fees, as well as some expenses that the owner has reduced for the construction unit, these expenses have been included in the contract price and are often easily deducted during settlement (such as labor insurance co-ordination, sewage charges, utilities, etc.). ). Track and audit the project, and the cost engineer can calculate and audit the completed project at any time, without waiting for the completion acceptance before settlement. 6. Making process control chart can be more intuitive, clear, logical and relevant. The whole process cost control management flow chart is a chart to determine the program requirements such as expense declaration, review and feedback, including responsibility relationship chart, monthly workload report and project payment flow chart, design change and verification single (visa) expenditure operation flow chart, material (equipment) quotation expenditure review flow chart and phased project budget (settlement) calculation flow chart. 7. Specific operation methods The whole process cost control is different from the traditional control mode of one-time investment to verify the project cost at the time of completion settlement in terms of service scope, consulting content and work nature. Whole process cost control implements dynamic, ex ante and active cost control on the whole project cost. The monitoring performance of project cost is from rough to fine, from lag to advance, which can better adapt to the changes of market economy and the needs entrusted by owners. Through decomposition, inquiry, investigation and other methods, the unit project is decomposed into several sub-projects, and the project settlement is handled in stages. Materials (equipment) quotation and inquiry, professional newspapers, information networks, etc. Used for inquiry; Visit suppliers or conduct market research to obtain relevant quotations and information. Of course, the original intention of the whole process control of project cost is not to reduce the profit space of contractors. Owners and contractors should be win-win partners, not conflicts of interest. The ultimate goal of cost control is to reduce unnecessary waste and avoid improper settlement by contractors. Cost control should be controlled not only from the macro, but also from the micro and specific details, changing the past static management mode based on quota and opening up a new management mode.