The Design for Safety (DFS) methodology involves eliminating or mitigating hazards by engineering design. Addressing safety early in the design process has the most benefit (Hagan, 2001) as opposed to attempting to manage hazards in service. The benefits include significant reduction in injuries, increased productivity, reduced operating costs, and reduced retrofitting.
The DFS model starts with hazard identification and risk assessment followed by implementing appropriate action(s) to eliminate the hazard or reduce the risk to an acceptable level. The design options from highest to lowest priority include eliminating the hazard(s) by engineering design, incorporating safety device(s), applying warnings, operating procedures/training, and personal protective equipment. DFS applies to the design of facilities, hardware, equipment, tools, job tasks, machines, consumer products, and more.
The application of DFS to construction projects is a relatively new idea. It goes against the "traditional" approach to a construction project where safety is managed after the project is underway, long after the design professional has completed the plans and specifications. The Designing for Construction Safety (DfCS) model extends the designer's role to include construction site safety, constructability, and maintenance in the design phase. DfCS provides new opportunities for designers to apply their skills to positively impact construction safety.
There are a number of resources that available to design professionals. These include a website (www.designforconstructionsafety.org), a 2 to 4 hour course for design professionals, and the Construction Industry Council CDM Guidance for Designers.
The number of construction fatalities is disproportionate to the size of the workforce. Construction makes up only 5.5% of the workforce, but has 21.5% of the fatalities. There are 1226 fatalities each year and 200,000 serious injuries. That's about 100 workers killed every month. For every worker killed there are about 160 workers injured (BLS 2006).
In general industry, design and fabrication takes place under one "roof". The design engineers, the machine shop, and the assembly workers are all employed by the same entity. The responsibilities are well defined. If the design engineer has a question on how his design will be implemented, he/she can walk downstairs or down the hall and ask the machine shop. Assembly is streamlined. Sequencing problems are worked out ahead of time.
Construction is different. The design professional and fabricator (contractor) are not under the same "roof". They are two separate entities bound by separate contracts. Under the conventional approach to a building project the owner separately contracts with an architect/engineer and with a general contractor, prime contractor, construction manager, program manager, or owner's agent. An owner may choose to contract with a design/build firm to perform both design and construction.
Design professionals prepare plans and specifications that comply with state and local building codes. The plans and specifications are legal documents that communicate the details on how the building should be built to the contractor. The codes contain minimum requirements to protect the public by addressing the safety and integrity of the finished product (the completed building).
