Management believes that process management is a series of interrelated and interactive activities, which transform input into output. All work is achieved through "process". Therefore, PDCA cycle in project management is also a process management. Controlling every process in PDCA cycle can provide corresponding solutions for cost management. Management also believes that management is a gradual process, and the improvement of management level depends on continuous learning. Therefore, construction enterprises can master higher management skills only after mastering lower management skills. Therefore, a practical project management method is needed.

PDCA cycle emphasizes the whole process management of planning, execution, inspection and treatment. In order to monitor the project cost in real time, it is necessary to know the progress of the project at any time, that is, when and which processes were implemented, and summarize these processes. This requires a detailed and clear project progress schedule. While monitoring the actual progress of the project, it is also necessary to compare it with the plan or budget made in advance and give feedback in time, so as to find the deviation at any time and correct it immediately to ensure that the project development conforms to the target direction. The principle of this process is simple, but the process control is difficult. The reason is that the statistical data of different nodes in different time periods during the project implementation is too large for people to even think about. It needs to make a feasible plan under the guidance of the previous actual plan, and link it to each process or node to compare with the actual situation. This kind of work needs not only the assistance of modern tools, but also the cooperation of various departments, which is not only realized at the ideological level, but also a comprehensive tool.

2. The convenience brought by the project cost management information system to cost management.

The construction project cost management information system uses the rapid calculation and statistical functions of the computer to solve the process management problems in the process of project implementation. Through the information system, the responsibilities of each department are clarified, the smooth handover of the work of each business port is realized, and the cooperation level and work efficiency of each department of the project department are improved. With the further clarification of the current market demand, the construction project cost management information system is constantly improving, which also points out a direction for the development of the construction industry. Products and services that conform to the project management direction of construction enterprises are very important, so it is inevitable to study the project management direction of construction market.

3. The information construction of project cost management needs innovative business process reengineering.

Management informatization is a systematic project, attracting a brand-new management concept, management method and management mode, which will have a great impact on the working style of every employee and change people's way of thinking. Therefore, the promotion of management informatization can only be gradual, not overnight. The construction of management informatization needs to constantly recreate the business process of enterprises with innovative spirit, so that enterprises and employees can gradually adapt to the impact brought by management informatization.

The traditional business process of construction enterprises is segmented, and the focus of each segment is only a single task and work, rather than the global optimization of the whole system. There are many problems such as chaotic management and ineffective business process duplication. In the construction of management information system, if we only use computer system to simulate the original manual management system and digitize the original business system, it is impossible to fundamentally improve the competitiveness of enterprises.

According to the characteristics of information technology, BPR fundamentally rethinks and designs the business process formed in manual mode, and needs to break through the traditional thinking mode, management method and organization and integrate the original business process. BRP is an important way to improve the efficiency of enterprise project operation, an insurmountable stage for enterprises to realize management innovation, a profound change in management foundation and a process of management innovation. Only this kind of "thoroughly remould oneself" reform can make the project management of enterprises get rid of the predicament completely and regain a new life. Management information system embodies advanced management ideas, and BPR is the essence of management information system from beginning to end. Management information system can be regarded as a means in the implementation of BPR. The two complement each other and are indispensable.