Stages and phases of the design and AVEVA Unified Engineering

The stages of a design outline the broad milestones in a project's timeline and highlight the main objectives during each period. Each stage may consist of one or multiple phases and focuses on a key aspect that requires further detailing.

The Key Stages and Phases are broken down in the following project stages. AVEVA Unified Engineering focuses on the project stages marked with .

1. Identify Stage — Inception and Feasibility Phase

   This is the initial phase where the needs and requirements of the plant are identified. This can include understanding the purpose of the plant, initial feasibility studies, and identifying potential risks.

   • Exploration, analyze, and identify concepts.

   • Strategic fit and business case development.

   • Preliminary planning, feasibility, budgets, resource and due diligence.

2. Evaluate Stage — Conceptual Design Phase

   Once the requirements are identified, various solutions or designs can then be evaluated to determine the best approach.

   • Define project objectives, scope, and requirements.

   • Conduct feasibility studies, alternate options, and site assessments.

   • Develop a preliminary Process Flow Diagram (PFD) and Heat and Material Balance (H&MB).

3. Define Stage — Front-End Engineering Design (FEED) Phase

   After evaluating the options, the chosen design is then defined in more detail. Initially led by the process department, at this stage more disciplines are engaged for their preliminary designs.

   • Develop a detailed PFD and H&MB.

   • Create a piping and instrumentation diagram (P&ID).

   • Determine equipment specifications and sizes.

   • Conduct hazard and operability (HAZOP) studies to identify potential risks.

   • Prepare a preliminary cost estimate.

4. Execute Stage — Detailed Engineering Design Phase

   This phase includes detailed engineering designs and equipment specifications. Develop detailed P&IDs, which includes instrumentation and control systems.

   • Design equipment layouts and piping arrangements.

   • Specify and procure major equipment and materials.

   • Create electrical and instrumentation designs.

   • Develop control system logic and safety systems.

5. Execute Stage — Procurement and Construction Phases

   As well as the actual procurement and construction or implementation of the plant based on the defined designs.

   • Issue construction and procurement packages.

   • Select contractors and subcontractors.

   • Monitor construction progress and quality.

   • Perform inspections and quality assurance.

6. Execute Stage — Commissioning and Startup Phases

   Post-construction, the commissioning phase ensures all systems and components are tested and meet operational requirements through activities like equipment testing and safety checks. Following commissioning, the plant begins its initial operation by introducing raw materials. Adjustments are made for optimal operation, with operator training and close monitoring to ensure alignment with design intentions.

   • Test equipment and systems.

   • Verify process performance and safety measures.

   • Train operators and maintenance personnel.

   • Start up the plant in stages, ensuring safety at each step.

7. Operate Stage — Operations and Maintenance Phases

   After the successful startup and stabilization of the plant's operations, the design enters the continuous operational phase. This phase focuses on the day-to-day running of the plant, ensuring it operates efficiently, safely, and in compliance with regulations.

   • Continuously monitor and optimize plant performance.

   • Conduct routine maintenance and inspections.

   • Implement safety and environmental protocols.

   • Handle any required modifications or upgrades.

   • Ensure compliance with local, national, and international regulations and standards such as The American Petroleum Institute (API), The American Society of Mechanical Engineers (ASME), and The International Organization for Standardization (ISO).

Stages 2 to 4 provide the foundation for the subsequent phases, which ensure that the project's objectives are well-defined. Technical aspects are thoroughly considered, and the risks are identified and addressed. These stages also serve as the basis for cost estimation and project financing decisions. The transition from conceptual design to detailed engineering design involves increasing levels of detail and refinement, with a focus on achieving a robust and efficient design.

The workflow described for the Conceptual Design, FEED, and Detailed Design stages of designing a process plant is based on industry best practices and commonly followed guidelines.

Industry standards and practices are often developed and maintained by organizations such as API, ASME, and ISO. These organizations provide guidelines and standards that influence how projects are planned and executed in the oil and gas industry.