Level of detail

In the context of process plant design, Level of Detail (LoD) refers to the extent and granularity of information and specifications that are provided in the design documents. This LoD is crucial as it affects the accuracy of cost estimations, the clarity of scope, and the efficiency of project execution.

The LoD generally follows these phases:

• LoD 1 (or 100) — Conceptual Design

• LoD 2 (or 200) — Basic Design or Front-End Engineering Design (FEED)

• LoD 3 (or 300) — Detailed Design (Development)

• LoD 4 (or 350) — Detailed Design (Completion)

It is important to note the critical difference between LoD 3 (or 300), to which our design tools aspire, and LoD 4 (or 350). Both LoD 3 (or 300) and LoD 4 (or 350) fall under the category of detailed design but represent different degrees of completeness and specificity.

The key differences between LoD 3 (or 300) and LoD 4 (or 350) are the following:

• Degree of Completion — LoD 4 (or 350) represents a more complete and finalized version of the design as compared to LoD 3 (or 300).

• Accuracy and Detail — The level of accuracy and detail in engineering drawings and specifications is higher in LoD 4 (or 350).

• Ready for Construction — LoD 4 (or 350) provides a package that is ready for construction, whereas LoD 3 (or 300) might still require additional development and refinement.

• Cost Estimations — Cost estimations are more accurate and reliable at LoD 4 (or 350) due to the higher level of detail and completeness.

In summary, LoD 3 (or 300) represents a developed stage of design with a significant level of detail, whereas LoD 4 (or 350) represents the completion of the detailed design phase, where the design is ready for construction with all necessary specifications, drawings, and documents fully finalized and specified.

Consider a panel design at LoD 300, where you have the basic layout, dimensions, and component list. As you move to LoD 350, the design is refined to include detailed wiring diagrams and comprehensive Bill of Materials (BoMs), providing the fabricator with (or provided by the fabricator) a clear, exhaustive guide for precise assembly and installation. This transition ensures all components are accurately placed and connected, aligning perfectly with the final design intentions.