What is a Basis of Design (BOD)?
A Basis of Design (BOD) is an essential document for every project. It provides all the principles, criteria, assumptions, and special requirements needed for design decisions and calculations during the design phase. The BOD is prepared by the Engineer or Designer with input from all departments, often by process engineers for oil and gas projects.
How to Write a Basis of Design for a Project?
Writing a Basis of Design (BOD) for a project requires careful consideration of the project goals and objectives, as well as the various business expectations, criteria, considerations, rationale, special requirements, and assumptions. All of this information should be included in the document in order to provide a comprehensive overview of the project. Additionally, the BOD should clearly outline the responsibilities of each department involved in the project.
What is a Basis of Design Document?
An Overview of BODs
The Basis of Design (BOD) document is an essential document used during the pre-design stage of a project that outlines the technical approach and preliminary project technical details. A BOD serves as the basis for all design calculations and decisions and includes a list of items to support the design process.
Dynamic Nature of BODs
The BOD is a dynamic document that is updated as the design process progresses. It includes specific descriptions of systems and components, their functions, relationships to other systems, sequences of operation, and operating control parameters. However, BODs do not include detailed project information or calculations.
1.Purpose of a Basis of Design Document
The Basis of Design (BOD) documents the major processes and assumptions behind specific decisions made during a project’s design phase. It is an essential document that concisely captures the owner’s requirements and vision into technical terms and design parameters. The BOD is a critical document for the commissioning team to evaluate the design, and it provides a listing of all major design decisions. Additionally, the document serves to provide a technical document on the thought process of design professionals for developing the plant and its life cycle cost analysis.
2.Responsibilities of the Basis of Design Document
Designers and engineers are responsible for creating and managing the Basis of Design document. They are responsible for ensuring the document is complete in all respects. The client and commissioning manager review and approve the document. Creating a quality Basis of Design is essential for the project’s success by improving the communication and collaboration between the design consultant and client.
3.How to Write a Basis of Design (BOD)
Writing a basis of design specification starts with the owner’s project requirement document. This document provides the necessary data to begin writing the BOD. The important parameters that are typically included in the basis of design for oil and gas projects include the type of equipment, process design parameters, safety systems, instrumentation requirements, and engineering standards. Additionally, the document should include a description of all the components, any assumptions made during the design process, and the timeline for completion.
Project Background and Document Purpose
The project background section of the basis of design document provides an overview of the project and its purpose. The document purpose section outlines the requirements of the document and the project scope.
Project Interface and Scope
The project interface section describes how the project interacts with other systems and processes. The project scope section provides detailed information on the overall scope of the project and the individual scopes of the disciplines involved, such as the process team, piping team, pipeline team, civil team, control and automation team, and electrical team.
Design Basis and Philosophy
The design basis section provides design information and assumptions for each discipline. This includes sub-modules such as process design basis, piping design basis, pipeline design basis, civil design basis, electrical design basis, and C&A design basis. The design philosophy section includes sub-modules such as operating, control and safeguarding philosophy; sparing and maintenance philosophy; metering philosophy; sampling philosophy; design philosophy based on H2S content; vent and drain philosophy; tie-in and shutdown philosophy; manning philosophy; pigging philosophy; emergency shutdown philosophy; technical safety; fire and gas philosophy.
Technical Assurance Review
The technical assurance review section ensures the safety and quality of the project by performing various quality reviews such as design review, HAZOP study, SIF, alarm rationalization review, etc.
Design Criteria
The design criteria section provides the basis for calculations such as sizing criteria for pipes/pipelines, capacity determination for partial relief valve, sizing criteria for partial relief valve pit, sizing criteria for chemical injection (demulsifier) skid, design life, and site environmental conditions.
Codes and Standards, Government Laws and Regulations, and Process Specification
The codes and standards section lists all relevant codes and standards with their editions. The government laws and regulations section outlines applicable laws and regulations. The process specification of the technology provider is outlined in this section, if applicable.
References and Appendices
The references and appendices section includes references and appendices to substantiate the project design decisions. This section is the final section of the design basis document.