3　System Design

3.1　General Requirements

3.1.1　Design of plant information system shall follow the principle of secure，reliable，cost effective，practical，open，extensible，technically up-to-date，integrated and optimized.It shall comply with the following requirements:

1　Modularized and standardized system architecture shall be used to support flexible configuration，function expansion and performance improvement as well as sustainable business process reengineering.

2　Design of plant information system shall satisfy requirement for business，and highlight execution performance and proper investment.

3　Mature products proven in the industry and commercialized at home and abroad shall be used，as well as open and commercialized and integrated platforms.

3.1.2　Plant information system shall be a main part of planning and project engineering for enterprise or plant，and shall be coordinated with process，instrument and telecom disciplines.

3.1.3　Plant information system shall be generally planned and executed by steps.

3.1.4　Feasibility study，overall design，basic engineering design（BED）and detailed engineering design（DED）stages for plant information system shall include the following contents:

1　At pre-feasibility study and feasibility study stage:develop the study reports，determine the overall targets，basic architecture and basic functions，provide the inputs for system investment estimate and costbenefit analysis and complete system planning and design to provide a basis for decision-making.

2　At overall design stage:develop the overall design documents，determine the design scope，principles and criteria，define the system targets，overall architecture，main functions and performance requirements，specify the operation and maintenance modes and organization，post assignment and staffing，propose the inputs for preliminary cost estimate，and complete the design of overall plan for plant information system.

3　At basic engineering design（BED）stage:develop basic engineering design documents，determine the design basis，applicable standards and codes，detail system targets and overall architecture，define the requirements and selection principles for the logic structures，functions，performance，protocols and interface of each system and its components（sub-system，devices），specify the selection principles，main performance indicators and environment requirements for devices and materials，define the interfaces and integration methods between systems，specify the organizations and staffing，propose inputs for cost estimate，and complete basic engineering design of systems and their sub-systems.

4　At detailed engineering design（DED）stage:develop detailed engineering design documents，further improve detailed engineering design，determine the specific plans，methods，construction drawings and their descriptions for system arrangement，deployment and construction/execution，provide the inputs for revising cost estimate or budget，and complete the construction/execution plans for systems and their subsystems.

3.1.5　All sub-systems of Infrastructure，PCS，MES and ERP in plant information system shall be designed，implemented and operated in parallel with the main plant development.