Detailed Engineering is the final phase of engineering where the design and plans developed during the FEED (Front-End Engineering Design) stage are finalized and elaborated into construction-ready documents.
Below are the key deliverables of the Detailed Engineering phase:
1. Final Piping and Instrumentation Diagrams (P&IDs - IFC)
Fully detailed diagrams showing all piping, valves, instruments, control loops, and safety devices, with all specifications, materials, and tags finalized. These P&IDs are issued for construction and serve as a primary reference for installation of equipment, piping and instrumentation.
2. Detailed Equipment Specifications and Datasheets
Equipment specifications from vendors for every piece of equipment, detailing design parameters, dimensions, nozzle schedule, materials, operating conditions, performance requirements, and any specific vendor instructions is assembled in this phase.
3. 3D Piping Model and Isometric Drawings
The 3D piping model is finalized in this phase and final isometric drawings of all piping systems, showing dimensions, elevations, materials, and connection details is prepared for fabrication of piping. The isometrics are also used to perform stress analysis and design necessary supports for piping.
4. Electrical Single-Line Diagrams (SLDs)
Finalized detailed single-line diagrams showing the complete electrical distribution network, including all power sources, switchgear, transformers, motor control centers, and connections to major equipment is prepared.
5. Wiring and Interconnection Diagrams
Diagrams showing the wiring and interconnections between all electrical components, including power supply, control systems, instrumentation, and safety devices is prepared for installation and commissioning.
6. Instrumentation Loop Diagrams
Detaield diagrams for each control loop is established, showing the connection and interaction of sensors, controllers, actuators, and other instrumentation.
7. Detailed Structural Drawings
Final drawings and calculations for all structural components, including foundations, supports, platforms, and buildings are put together. These documents ensure that the structures are safe, stable, and compliant with engineering standards adopted for the project.
8. Civil and Architectural Drawings
Final detailed drawings for site preparation, grading, drainage, roads, buildings, and other civil works is generated. Final architectural drawings include layouts, elevations, and finishing details for buildings and control rooms are also prepared.
9. Mechanical Equipment Installation Drawings
Final Drawings based on vendor data showing the installation requirements for all mechanical equipment, including foundations, alignment, piping connections, and mounting details is prepared to support installation of equipment.
10. Control System Design and Configuration
Final design documents for the Distributed Control System (DCS) or Programmable Logic Controller (PLC), including control logic, Human-Machine Interface (HMI) design, alarm management, and network architecture is developed. This includes software programming and configuration instructions.
11. Updated Project Execution Plan
The project execution plan issued at the end of the Detailed Engineering phase outlines all activities, from procurement and construction to commissioning and startup. The schedule includes critical paths, resource allocation, and milestones for tracking progress.
12. Procurement and Vendor Documents
Purchase orders, vendor drawings, inspection and test plans, and delivery schedules for all equipment and materials is prepared.
13. Material Take-Off (MTO)
A comprehensive list of all materials, including piping, steel, concrete, electrical cables, and instrumentation components. The MTO is used for procurement, cost estimation, and inventory management.
14. Total Installed Cost Estimate (Class 1)
The Total Installed Cost Estimate is updated from the Pre-FEED phase based on the availability of more engineering data on equipment, piping, instrumentation and civil/structural elements. A comprehensive breakdown of costs, including equipment, materials, labor, construction, and contingencies. The accuracy is typically ±5 to 10%, making it suitable for final budget approval.
15. Construction Work Packages (CWPs)
This is a key construction document. Packages that break down the construction work into manageable sections, including detailed drawings, material lists, procedures, safety plans, and schedules for each segment of the project is prepared. CWPs ensure that construction is organized, efficient and cost effective.
16. Test and Inspection Plans (ITPs)
Plans detailing the tests and inspections required for each component and system, including criteria for acceptance and procedures for non-conformance are put together. ITPs cover material testing, weld inspections, pressure tests, and electrical checks.
17. Safety, Health, and Environmental (SHE) Plan
Detailed plans and procedures for managing safety, health, and environmental risks during construction and operation is assembled. This includes hazard assessments, emergency response plans, and environmental protection measures.
18. Operating and Maintenance Manuals
Comprehensive manuals detailing operating procedures, maintenance schedules, troubleshooting guides, and safety instructions for all systems and equipment is developed. These manuals are essential for the safe and efficient operation of the facility.
19. Commissioning and Startup Plans
Detailed plans outlining the steps for commissioning each system, including pre-commissioning checks, system flushing, equipment startup procedures, and performance testing is prepared. These plans ensure a smooth transition from engineering to construction to operation.
20. As-Built Drawings and Documentation
As a final step in engineering, updated drawings and documents reflecting any changes made during construction are prepared for the operations team to use for the future. These "as-built" records are critical for future maintenance, modifications, and troubleshooting.