Prefabrication, Preassembly, Modularization, and Offsite Fabrication: Decision Framework and Tool, V
Prefabrication, preassembly, modularization, and offsite fabrication (PPMOF) have become more viable with recent advances in design and information technologies. Recent work force pressures also drive their use. The CII Modularization, Preassembly/Offsite Construction Project Team found that PPMOF offers a substantial opportunity to improve project performance and overcome external and internal project challenges.
Successful implementation of PPMOF requires systematic analysis and decision-making. Key factors influencing the decision-making, including new technologies and a changing construction environment, have expanded and changed in the last decade. This increases the need for the structured decision-making process described in this guide.
The project team extended prior CII research, identified state-of-the-art PPMOF practices, and developed a decision framework for the possible use of PPMOF. In developing the decision framework, the team focused on identifying the requirements for effective use of PPMOF on industrial projects. The framework includes a decision timing map, tools for strategic analysis, and suggestions for tactical analysis in the PPMOF decision process. It also includes a spreadsheet-based Strategic Analysis tool to assist in the process. The spreadsheet tool is included with this document. The tool and this document can be used separately, but are intended to be used together.
To realize the possible benefits, project managers need a solid framework for analysis and decision-making regarding the potential use of PPMOF in a project. This framework should be easy to maintain and independent of software platform. The framework presented here works in ExcelTM but can be followed with the use of paper forms as well.
Definitions
To provide a basis for classification of PPMOF, the project team used the following definitions in the research:
- Prefabrication: a manufacturing process, generally taking place at a specialized facility, in which various materials are joined to form a component part of a final installation. Prefabricated components often involve the work of a single craft.
- Preassembly: a process by which various materials, prefabricated components, and/or equipment are joined together at a remote location for subsequent installation as a sub-unit; generally focused on a system.
- Module: a major section of a plant resulting from a series of remote assembly operations and may include portions of many systems; usually the largest transportable unit or component of a facility.
- Offsite fabrication: the practice of preassembly or fabrication of components both off the site and onsite at a location other than at the final installation location.
