Functional Design Specification

The preparation of the Functional Design Specification (FDS) is arguably the most import stage in the design of any control system. Considered "Phase I" of a project, it includes a detailed description of the existing system as well as all of the specifications and recommendations necessary for an upgrade. The FDS provides detailed explanations of all design functions, operator interactions, control, and sequencing associated with the current and proposed new system. The FDS describes in detail the solution to be provided to meet the client's needs, and forms the basis of a system's Software and Hardware design.

A quality FDS saves the customer from unwanted surprises that may arise upon installation. The research and scrutiny that goes into an FDS catches potential problems and minimizes the number of change orders that would otherwise be necessary after the project is underway. Engineers use the FDS to verify and validate the system during testing, ensuring that all of the required functions are present and operating correctly. This allows the user to confirm that the proposed solution fully meets their requirements before the system is developed.

Qualities of a Well-Written FDS:

  • Functionality Focus
  • Completeness
  • Accuracy
  • Testability

Benefits of a High-Quality FRS:

  • Fewer questions by the implementation engineers, leading to increased productivity.
  • Consistent documentation allows engineers to easily float from area to area or project to project.
  • Less experienced engineers are able to do more on the project.

At Prism Systems, our engineers work closely with our clients to assess their current needs and work carefully to clearly detail what steps and materials will be necessary to achieve the user's goals, while catching any potential pitfalls they may encounter prior to installation.