Adaptation of Shipbuilding Production Systems to Construction

This has been identified as the number one benefit for adopting IPD modular construction techniques. Modular construction is occurring based on the IPD shipbuilding model with execution driven mostly by owners’ needs for faster project delivery. Case studies (listed in Table 1 in RS255-1) have shown that significant schedule compression is being achieved. The IPD methodology currently generates a substantial reduction in the engineering design time for ships – up to 80 percent. This savings on design is largely realized from the adaptive reuse of a standing database library of qualified and scalable designs, with very limited new design.

• Five case studies identified schedule improvements between 15 - 50% over original baseline schedules due to the modular approach that allows for paralleling activities, construction out of season. 
• Cost savings were marginal or non-existent.

Case studies have shown various implementation barriers exist to successfully execute a project based on the IPD model.  RT-255 identified 22 barriers grouped into the following six categories. (Reference RS255-1 Appendix, page 35 for a detailed construction methodology barrier analysis.)

1. Execution considerations (4)  
   1. Integration for reusable modular construction
   2. Customization
   3. Ability to scale and repeatability
   4. Plant capability
2. Design considerations (4)  
   1. Natural phenomena
   2. Site constraints
   3. Codes and standards
   4. Inspection and tests
3. Transportation considerations (5)  
   1. Travel distance and cost
   2. Road restrictions
   3. Handling capabilities
   4. Shipping and packaging
   5. Transportation risks
4. Module interface considerations (2)  
   1. Interface tolerances
   2. Ability to handle field changes
5. Labor considerations (3) 
   1. Labor at construction site
   2. Labor at fabrication area
   3. Labor agreement
6. Long-term methodology considerations (4) 
   1. Market size
   2. Initial funding
   3. Long term funding
   4. Regulations and codes

The research identifies virtually no data to substantiate the following, but there are common patterns that can be drawn from the five case studies:

1. Project Cost Savings – Economic benefits will be realized as projects move from the high-risk stick-built environment to an IPD modularized approach. However cost saving are marginal or limited in research studies to-date. Productivity differentials over field conditions were observed in modular facilities due to controlled conditions, closer supervision, and easier access to tools, but very little hard data suggests cost savings are identified. The report analyzes one case study regarding the economics of building an off-site modular manufacturing facility. 
2. Lower Material Cost – No specific material cost savings is identified in the case studies; however the research identifies potential savings through bulk purchases and economies of scale.
3. Improved Safety and Higher Quality – The prefabrication sites typically saw improved safety statistics over a site construction due to the safe, sometimes climate controlled, environment.  The environment reduced hazards and improved working conditions, thus improving both safety and quality. In addition, projects requiring stringent quality construction can benefit from a modular approach due to easy off-site verification of quality standards.  
4. Single Project Focus Impedes Modular Investment – The case studies identified the limited re-use of designs in the development of a core module library do to the specific design function of each project.  

Owners and contractors can continue to develop and adapt the IPD process by embracing the advantages of modular construction in the initial planning stages. In addition, they can continue to develop module design criteria that can be adapted and reused on future projects, which is identified as the single largest barrier to the future application of the IPD approach. As each project is undertaken, parametric rules for modifying and optimizing modules can be developed.