How to realize the lean construction mode of enterprise operation

The idea and technology of lean construction originated from lean production theory. Lean production is a production system composed of mobile products and fixed people, while architecture is a production system composed of fixed products and mobile people. Construction projects are complex and uncertain. Lean construction redesigns the project management process according to the idea of lean production, aiming at "multi-win and integrated delivery" under the conditions of ensuring quality, shortest construction period and least resource consumption.

In 1950s, Toyota Motor Corporation of Japan initiated the Toyota production mode. The theoretical system of Toyota's production mode aims at eliminating waste, with JIT and Jidoka as the two pillars and continuous improvement as the basis. After further research and development by academic and business circles headed by MIT, it has become a new management concept, namely lean thinking, in the mid-1990s. The application of lean thinking in manufacturing industry, that is, lean manufacturing, greatly reduces the manufacturing cost, shortens the development and manufacturing cycle, and significantly enhances the competitiveness of enterprises.

Compared with the manufacturing industry, the production efficiency of the construction industry is very low, the working conditions are bad, and the product quality is difficult to guarantee. Therefore, an advanced management method is needed to change this situation and improve the management level of the construction industry.

1992, Danish scholar Lauris Koskela proposed to apply the mature production principles of manufacturing industry, including lean management, to the construction industry in order to improve the management level of the construction industry, and put forward the concept of "lean construction" for the first time at the 1993 IGLC conference. After more than ten years of unremitting efforts by many advocates of lean construction theory, lean construction theory and achievements are increasingly rich, and the main research topics are as follows:

(1) Basic theoretical research;

(2) Research on production planning and control;

(3) Research on product development and design management;

(4) Design of building production system;

(5) Construction enterprise culture and innovation;

(6) Research on project supply chain management;

(7) Study and implement prefabricated components and open engineering projects;

(8) The combination of project management and information system;

(9) Safety, quality and environment;

(10) Contract and cost management.

Lean construction is a new delivery method of construction projects, which uses the concept of lean thinking to maximize profits and minimize waste to meet customer needs. The concept of lean construction can be divided into broad sense and narrow sense. From the whole life cycle of a building project, from planning, design, construction to final property management, lean construction should be applied to building products from the beginning, so as to truly ensure the production of high-quality and low-cost building products. Lean construction in a broad sense involves many departments, requiring construction units, design units, construction units and property management departments to implement lean construction in the process of building operation. In a narrow sense, lean construction only refers to the high-quality and high-profit construction carried out by the general contractor in the process of construction management.

The core of lean construction mode is to realize the standardization and continuous improvement of organizations and functions at all levels of construction enterprises through the step-by-step and planned application of management systems or methods, and gradually realize refinement, precision, lean and continuity. The implementation of lean construction mode is a systematic project, and the top managers of construction enterprises should establish lean construction ideas; Middle and senior managers in construction enterprises should build a lean management system; The grass-roots backbone of construction enterprises should apply lean construction management tools.

The "Fiona Fang Map of Project Cost Management" put forward by China Construction Fifth Bureau is a typical application of lean construction mode in the operation level of construction enterprises. On the basis of "Fiona Fang", Fiona Fang Chart of Project Cost Management comprehensively and systematically expresses the key influencing factors of project economic management, summarizes a set of scientific management mechanisms and methods of "reducing costs and increasing efficiency" of the project, and reflects the thinking on the concepts of cooperation among project management stakeholders, big cost, full responsibility and main line of cost.

Figure: Fiona Fang project management cost chart.

Construction enterprises generally adopt a purposeful, one-time and specially authorized organizational model of project management department to systematically manage the overall performance of the project from two levels: the company and the project department. Project management is the cornerstone of enterprise management, cost management is the cornerstone of project management, project economic management should take cost management as the main line, and do a good job in project cost management should implement four basic concepts.

(1) The concept of harmonious * * * win among stakeholders in the excircle.

In the excircle, "circle" means "Tong Yuan", representing thoroughness and flexibility; "Fang" means "founder", which means steady and rigorous. The combination of Fiona Fang's foreign economy and domestic economy is a general plan of governing the country that China has inherited for more than 2,000 years. It is an image interpretation and intuitive interpretation of a management philosophy, and it is the concept that all parties in project management can live in harmony and win-win cooperation.

(1- 1) external "circle": external open source management should be "circle"-thorough thinking, broad thinking and diverse methods. It is reasonable to talk about "circle", that is, we must pursue the maximization of operating benefits and settlement benefits within the framework of law and contract. "Circle" emphasizes initiative and coordination.

(1-2) internal "prescription": internal management of throttling should be "prescription"-strict system, systematic management, scientific planning, clear responsibilities and measures in place. There is a basis for emphasizing "Fang", that is, low cost is not shoddy, fraudulent and Jerry-building, but to control all costs within a reasonable target range on the premise of achieving the project quality, safety, construction period and environmental protection goals. "Fang" emphasizes norms, supremacy of rules and bottom line control.

(2) The concept of big cost of project productivity optimization.

The optimization of project productivity is to realize the optimal allocation of production resources (elements) in the process of project management and realize the management goal of meeting the performance requirements most reasonably. Project cost management should have the concept of big cost, and scientifically allocate and manage productivity factors such as technology, labor, materials and machinery and management objectives such as time limit, quality, safety and environmental protection.

The optimization of project productivity must also emphasize the corresponding production relations. For construction enterprises, the project is the object of enterprise management and the foothold and starting point of enterprise management. Enterprise is the operation control center of the project, and the decision-making power on the allocation and use of production resources of the project belongs to the enterprise level. The production relations that play a role in the development and improvement of the project productivity are ultimately formed and decided by the enterprise level, and the improvement of the average productivity level of the project depends on the improvement of the overall management and control level of the enterprise. Therefore, this requires that the enterprise level must establish a good order of production relations for the project through continuous system improvement, mechanism optimization and cultural construction, and constantly create a good project management environment and management platform through transformation, upgrading and innovation and development, which is what we usually call "enterprise management project".

(3) The concept of overall responsibility with the unity of responsibility and rights.

Generally speaking, there are three things in the operation of a construction enterprise: "receiving work", "working" and "collecting money after bookkeeping". Enterprise management is to establish a mechanism to do these three things well and truly implement the responsibility system for all employees. We put forward three major responsibility systems for project management, namely, marketing manager responsibility system, project manager responsibility system and project settlement responsibility system, and emphasized three different responsibility mechanisms to implement various tasks, which reflected the concept of full responsibility with clear responsibilities and rights between enterprises and projects. "Receiving work" is a "one-time operation" of construction enterprises, mainly to connect with "market"; "Part-time job" is the "second operation" of the enterprise, mainly to manage "site"; "Collecting money after checkout" is the "three tasks" of an enterprise, mainly to complete "clearing the field". Whether an enterprise can establish a comprehensive, systematic, effective, scientific and reasonable responsibility system around docking the market, managing the site well and clearing the field is the key to ensure the effective operation and sustainable and healthy development of the enterprise.

(3- 1) "succession" is the first major event for construction enterprises. To accomplish this great event, enterprises must establish an effective marketing responsibility system and working mechanism, and the marketing management department is an effective organizational form to implement the marketing responsibility system. The marketing management department is the one-time responsible subject who applies the project management principle to the marketing stage, effectively organizes the marketing resources of the enterprise, and thus completes the first working procedure of the construction enterprise-"receiving orders". Its main responsibility is to obtain a certain number of "orders" in a certain period of time according to the business strategy and annual work requirements of the enterprise, and at the same time, the enterprise must make a certain investment and pay a certain fee and cost. Enterprises take "operating efficiency" as the core index to evaluate and measure the marketing management department, which is the main basis for rewarding and punishing the marketing management department, especially the marketing manager.

(3-2) "Work" is the second major event of construction enterprises, and it is also the main task and main "process" of construction enterprises. Usually, after receiving the "order", an enterprise needs to set up a project management department according to the characteristics of the project and the requirements of the contract, and then organize effective resources to complete the construction task. Project management department is an effective organizational form and one-time management responsibility subject entrusted and authorized by enterprise legal person to complete the production process of engineering projects. The main indicators for evaluating the project management department include "management benefit", which is the synthesis of time limit, quality, safety, environmental protection and cost. "Management benefit" is the main basis for evaluating project management departments, especially project managers.

(3-3) "Settlement and collection" is the third major event for construction enterprises. Under normal circumstances, it takes a construction enterprise one to two years or even longer to complete the project settlement and project payment recovery after the project is completed, which requires the enterprise to organize special manpower and material resources and establish a certain responsibility system for settlement and collection to complete the important task of "settlement and collection". "Settlement Collection Team" is a one-time organizational form similar to "Project Management Department". Their assessment must also establish a certain target management responsibility system, that is, to achieve certain goals, achieve certain achievements and give certain rewards within a certain period of time. "Settlement benefit" is the main index to assess the responsibility group of "collecting money after settlement".

(4) The main idea of cost in economic management of engineering projects.

Project management is a systematic management. As the cornerstone of construction enterprise management, project management is the platform for building enterprise brand, the source of enterprise profit and the key link of social reproduction. Project cost management must be the main line of project management. Project management takes cost management as the main line to embody two aspects: First, it embodies the concept of "big cost" of all employees in the enterprise. It is necessary to clearly understand the complementary relationship between low-cost competition and high-quality management, realize the goal of low-cost competition with high-quality management, emphasize that the project can reduce costs and increase efficiency on the basis of fully realizing the management objectives of time limit, quality, safety and environmental protection, and realize sustainable development through optimized management and cooperation of relevant parties. The second is to reflect the whole process of the project cost concept. In other words, employees in all positions of enterprises and projects must strengthen their cost awareness and be responsible for their own cost responsibilities.

Through systematic analysis and exploration, a "Fiona Fang Map" can be used to comprehensively show the five management elements, three responsibility systems and five cost components of project management, and the whole is a geometric figure composed of "three realities and three imaginary" and "two circles and three parties". It vividly describes the control points (two costs, three costs, four fulcrums and five major expenses) and concerns (three benefits) of project cost management. The solid line and dotted line respectively represent the relatively fixed and variable contents in the management process, and the three colors of coffee, blue and gold respectively represent the project management benefits, management benefits and settlement benefits. The management benefit, management benefit and settlement benefit of the project, the contract cost, responsibility cost, target cost, actual cost and total settlement price of the project, the five major construction costs of the project, such as labor cost, machinery cost, material cost and site cost, and the four supporting points (main management objectives) of project management, such as quality, safety, construction period and environmental protection, are vividly displayed in a "Fiona Fang" figure.

(1) Docking two "circles" of the market.

Outer ring: the total settlement price of the project. Including the settlement price of engineering entities, engineering changes, visa claims, incentives, etc. Affected by the level of settlement management in the process of the project, the boundary can be determined after the project is completely completed, which is indicated by a dotted line. Inner ring: project contract cost. At the beginning of the project, it is determined by the contract and indicated by a solid line.

(2) Three aspects of internal management.

Foreign party: project responsibility cost. According to the bidding cost calculation and contract negotiation conditions, the highest cost determined by the enterprise to the project management team is generally fixed in the project management target responsibility book, which is represented by a solid line. Chinese side: target cost of the project. At the beginning of the project, the amount of internal control target cost determined by the project management team is generally fixed in the project planning and represented by a solid line. Internal: the actual construction cost of the project. It consists of five parts: labor cost, material cost, machinery cost, weekly material cost and site cost. Influenced by the project process cost management level, the boundary can be determined after the project is completed, which is represented by a dotted line.

(3) Four supporting points.

Quality, safety, time limit for a project and environmental protection are the four basic objectives of project site performance and the four most important management processes of project cost formation, which are embodied in four pillars and framed in the whole "Fiona Fang Diagram".

(4) separation of three benefits.

(4- 1) Operating benefit is the income gained by the brand and comprehensive strength of an enterprise. When undertaking the project, it shall be determined by the terms of the construction contract and the winning contract. Divided by "contract cost" and "responsibility cost". Enterprises use "operating efficiency" to measure and evaluate the performance of marketing personnel, and implement the marketing manager responsibility system in the form of marketing target responsibility book.

(4-2) Management benefit refers to the benefit obtained by project managers through strengthening management and saving actual costs on the basis of established project responsibility costs. Divided by "responsibility cost" and "actual cost". "Management benefit" is the main index to evaluate the performance of the project management department, and it is also a symbolic index to measure the contribution of the project management team. The project manager shall sign a project management target responsibility letter with the enterprise and implement the project manager responsibility system.

(4-3) Settlement benefit is the benefit obtained through optimized management without increasing the construction cost; Some are accrued according to market rules or contract provisions; There are also some expenses that should have occurred according to the average market management level, but they have not occurred or less because of the adoption of new technologies or methods. However, according to the market pricing rules and related policies, it can be calculated from the owner. In order to embody and implement the responsibility system for collection, enterprises must also sign a responsibility book for work objectives with the collection team as the basis for assessing and rewarding relevant personnel.

(5) Arrangement of five expenses.

(5- 1) cost item: in the Fiona Fang diagram, the direct construction cost of the project is not divided into seven standard categories according to the usual project cost, but divided into five major cost expenses, which combine "other direct expenses" and "indirect expenses" into what we are used to saying "site expenses", and at the same time increase the "weekly material expenses" and "indirect expenses" which are difficult to control on-site materials.

(5-2) Arrangement order: The five expenses in the "Fiona Fang Diagram" should be analyzed clockwise from the middle and from the upper left corner. The first material cost is the largest cost of the project entity and the primary control goal; Labor costs, machinery costs and site funds are completely consumed in the process of project implementation, and labor costs rank in the upper left corner, which means that the labor factor is the most active factor among all productivity factors. Choosing a good labor operation team is the primary condition for the smooth development of the project construction, which needs the focus of the project management department; The weekly material cost is placed last, that is to say, the key to control the weekly material cost is to manage the on-site use and close the exit.

(6) the choice of three colors.

Set "commercial interests" as brown, and borrow the color of coffee or tea often used in commercial activities to express the interests formed by our marketing activities and marketing behaviors; Set "management benefit" to blue, and borrow the meaning of "blue collar", which means the benefit formed by the hard work of our front-line managers; Defining "settlement benefit" as gold, borrowing the meaning of "golden sun" means to pursue the maximization of profits under the sun. To expand "settlement benefit", we must abide by market rules, be reasonable, legal and compliant if we can advance and retreat, and exercise reasonable restraint to strive for the greatest interests for enterprises.

As a model of economic management of engineering projects, "Fiona Fang Diagram" not only contains the concept connotation and intuitive tools of management philosophy, but also systematically provides a set of concrete and practical construction management methods. It includes all the cost management links of construction enterprises and projects.

Lean construction is to build the whole project delivery system based on lean production theory and architectural production theory. The theory of architectural production mainly includes four parts: production theory, lean thinking, project management theory and TFV production theory based on architectural particularity management theory. TFV production theory understands the process of building life from three angles: transformation, mobility and value production. By implementing task management, process management and value management, we can minimize waste and maximize value while delivering the project.

On the basis of the above management concepts, lean thinking is mainly applied in the following aspects: customer demand management, design mode reform, reducing changes and improving performance, standardized management of engineering projects, and performance evaluation of project process. In the process of applying these application theories, there are many auxiliary technologies to support them, such as LPS, VE, JIT and so on.