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Automatic control engineering design includes several stages: the automatic control design process, the content of automatic control design, the review of automatic control design, cooperation in automatic control design, procurement cooperation, and construction cooperation. In a series of articles, CHANGHUI Instruments will introduce the tasks that need to be carried out at various stages, so as to provide instrument professionals with a comprehensive understanding of automatic control system engineering design. \"Engineering Design Procedures for Automatic Control System Engineering\" is the first article in the series on automatic control system engineering design. The engineering design process consists of three stages: project construction, engineering consultation, and engineering design, which are discussed in detail by Changhui Instruments in this article. Changhui Instruments, yunrun.com.cn – Automation engineering design procedures: 1. Engineering construction procedures. Engineering design is one of the stages in the process of engineering construction. Project construction usually includes the following processes: ① Project consulting ； ②Engineering design ； ③Engineering procurement ； ④Construction work ； ⑤The project was put into operation. In actual engineering projects, the tasks of engineering design, procurement, construction, and commissioning are often entrusted to a single party, a practice commonly known as turnkey project delivery, abbreviated in English as EPC. 2. Engineering consulting: The main form of engineering consulting is feasibility study. The main contents of a feasibility study include technical feasibility analysis, market feasibility analysis, economic feasibility analysis, and comprehensive analysis conclusions. The analysis process and the conclusions derived from it are used to formulate a feasibility study report. The report determines the feasibility of the project and recommends a viable technical approach. After the preparation of the feasibility study report, the project owner shall conduct a review. After the review is completed, the entity responsible for preparing the feasibility study report makes the necessary revisions and improvements based on the feedback received, and then submits it to the higher-level authority of the project owner for further review. After the higher-level authorities have completed their review, the entity responsible for preparing the feasibility study report and the project owner work together to make modifications and improvements based on the feedback from those authorities, before submitting the document again to the same reviewing body for further examination. Upon approval by the higher authorities, this feasibility study report will serve as the basis for project construction and engineering design. Feasibility studies do not fall within the scope of engineering design. However, domestic design firms generally possess technical consulting qualifications, and feasibility study reports for domestic engineering projects are usually prepared by engineering design firms as well; therefore, feasibility studies are often mistaken for engineering designs. 3. Engineering design: The engineering design is divided into several stages. In the early days, domestic engineering was divided into overall design, preliminary design, and construction drawing design. Currently, engineering design can be divided into at most five stages: process package design, conceptual design, preliminary design, basic design, and detailed design. When the design unit acts as the EPC general contractor, as-built drawings also need to be prepared. Process package design is not a regular design phase; it is only required when the process equipment is purchased as a complete set along with its process technology. The overall design is not a conventional design phase. For large and medium-sized engineering projects that consist of multiple production units, an overall design is prepared to better coordinate the material flows, energy flows, demand relationships, interface connections, and so on among these units. The preliminary design is not a conventional design phase. Under normal circumstances, domestic engineering projects do not have this design phase, whereas foreign projects do (abbreviated in English as FEED). It is equivalent to the basic design in China. The design phase appears in an engineering project only when the process equipment requires a design at that level of depth. The basic design is the conventional design phase. It was originally called the preliminary design. The detailed design is the conventional design phase. It was originally called construction drawing design. Some owners adopt a single-phase design approach for projects with mature process technologies and clear investment returns, that is, they proceed directly to detailed design. After each phase of design – such as process package design, overall design, preliminary design, and basic design – is completed, the client shall conduct a review. The reviewed documents serve as the basis for the next phase of work. After the detailed design is delivered, the project owner shall organize the construction contractor to conduct a design review and design briefing. During the construction of a project, it is necessary to modify the original design due to reasons such as design corrections, design improvements, owner’s requests, equipment replacement, or substitution of materials; this is referred to as a design change. After the construction is completed, the detailed design is revised in accordance with the design changes to produce the as-built drawings. In the early days, the as-built drawings were the responsibility of the construction contractor. In recent years, the business of domestic design firms has gradually shifted from pure design to an EPC turnkey model that integrates design, procurement, and construction, with as-built drawing design becoming a standard part of their work. 4. Automatic control engineering: The design procedure for automatic control engineering is the same as that described in the previous section, and the work is carried out in synchronization. Technical approach for automatic control system engineering design: requirement analysis, project definition, design planning, document preparation, design services. ①Requirement analysis: Analyze the design inputs to clarify the requirements. Design inputs include the design contract, previous design documents, previous design review comments, existing condition data, project specifications, special reports, etc. ②Project definition: Determine the project scope, main project elements, level of automation, and primary solutions. ③Design plan: Break down the design elements and prepare a work plan. ④Document preparation: At each design stage, relevant design documents are prepared in accordance with the industry standards regarding the required level of design detail. The design documents for automation control systems mainly include: the Process and Instrumentation Diagram (abbreviated as P&ID in English), an instrument index table, instrument specifications, control system specifications, instrument installation diagrams, instrument piping and wiring diagrams, instrument air supply diagrams, instrument wiring diagrams, instrument power supply diagrams, instrument grounding diagrams, a summary table of instrument equipment, and a summary table of instrument materials, among other documents. ⑤Design services include construction coordination, design modifications, construction inspections, start-up coordination, and calibration support.