Definitive Design

One of the most important elements in an efficient enterprise electronic security program is the identification and/or development of a best in class design capability. Many of you are already scoffing at the so-called added expense a design effort represents, and I admit that as a licensed engineer I may have a bias toward this topic.

I also have A LOT of experience to back me up.

First, let’s define terms. The Construction Specifications Institute defines Contract Documents, of which design documents are a part, as legally enforceable terms and conditions containing graphic (i.e. design drawings) and written (i.e. specifications, general and supplementary conditions, etc.) elements. Fundamentally, the design documents take your functional requirements and translate them into language that is universally accepted by the construction/installation industry. I tend to think of a design package as consisting of three items:

Plans: Design drawings are very simply a pictorial representation of the finished system. Very simply, they locate components within the facility, define connectivity of the system components, and establish the manner in which the components will be installed.

Specifications: Specs define textually various requirements of the project that are not necessarily spatially dependent and therefore not easily represented on a drawing. Specs will address such items as warranties, software functionality, testing procedures, material requirements, and security component characteristics. In many cases where the scope of the project is limited and the equipment to be installed is determined, the specification-like instructions can be placed on the drawings.

Cost Estimate: Once the design drawings and specs are finished, it is a simple to create a bill of materials, assign material and labor costs, and produce a budgetary estimate of the total project cost. This material is essential in determining the appropriateness of an integrator’s bid for a project.

I hear a lot of reasons for not preparing design documents:

We have program standards: A lot of folks try to replace design documents with written program standards. Unfortunately, I have not seen this work well at all unless the program standards contain such things as standard installation details, equipment performance requirements or identification, and testing procedures. In other words, the standards start to look a lot like design documents.

They are too expensive and time consuming: A general rule of thumb is that a design effort may cost on the order of 10% of the installed cost of the system. On smaller projects that number usually goes up; with larger projects, it goes down. From my perspective, this is a small amount to pay to avoid the rework, disputes, change orders, and delays that come from a project that is not sufficiently defined. It is also a small cost increment to get what you want from the system.

We don’t need as-built drawings? I very rarely see as-built drawings for security systems; I never see as-built drawings for a system that was not designed. The design drawings form an excellent basis for the keeping track of as-built conditions during installation and the final record as-builts when the project is complete. No as-builts means inefficient (i.e. expensive) maintenance and troubleshooting.

They are unnecessary: Gimme a break. Without definitive design direction, prepare yourself for something like the following:

And finally, (I really like this one)

In other words, without specific and definitive direction to the integrator, you will not get what you want.

Efficiencies in design can drive the cost and time down. Establish a long-term partnership with a security design firm. They will get to know your requirements and will learn how to quickly incorporate them into your projects. Have them develop standard installation details so much of the design simply becomes a matter of locating the major components. Standardize the major components so that much of the design details and specifying notes can be re-used from project to project. By implementing the above procedures, the design time for a typical project can be reduced from weeks to days, thus reducing the costs. You will also benefit from standardization across all of your projects, which will reduce your long-term maintenance costs.

Randy Nason, PE, VP