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Functional Performance Specification Technique

What is the Functional Performance Specification Technique?

Functional Performance Specification(FPS) is a technique to define the requirements of a project, product or service, based on the required Functions and the specific needs related to those Functions. The technique was originally developed in France to define the requirements of new products. The French term for the technique is Cahier de Charges Fonctionnel (CdCF)

The Functional Performance Specification (FPS) technique enables the owner to document their performance requirements in terms of functions and needs without reference to a specific solution. For each function, needs are expressed in terms of assessment criteria, levels of performance and a flexibility for each level

There are four stages for FPST: Need, a user's needs or desire. Function, A specific need performed by a product, process or project expressed in a verb-noun combination.. Specific Requirements, Requirements specific to each function expressed as an assessment criteria, level, and flexibility. Product, A unique solution provided to the user to satisfy the needs as defined.

Why is the Functional Performance Specification Technique useful?

Using the FPS technique, Needs and expected performance are expressed without reference to a specific solution. The client defines the needs in terms of what the solution must do, rather than what it must be. The Functional Performance Specification document provides a common understanding of project needs between the client and the supplier and it allows for a broader range of innovative solutions that meet the client needs.

Documenting needs through the FPS technique allows the owner to obtain innovative solutions that best meet the actual requirements. The development of an FPS encourages constructive dialogue with the client and enables the provider to express greater creativity in the delivery of solutions.

Using this technique to document needs changes the owner/supplier relationship from an obligation to respond to a predetermined technical specification to an obligation to achieve a result.

Where can the FPS Technique be used?

  • Defining project goals and requirements.
  • Identifying business needs to develop or improve business processes
  • Restructuring organizations.
  • Defining requirements for Design Build projects.
  • Establishing requirements for Information Technology Projects.
  • Developing Job Descriptions.

Steps in applying the Functional Performance Specification Technique:

  • Develop a Function Tree diagram for the project process or service under study.
  • Characterize each function by identifying and defining the applicable needs and constraints as follows:
    • Needs: Consider each function and identify the specific needs and requirements that must be met for this function to be satisfied.

    • Criteria: define all criteria that will be used to evaluate and/or measure if the function is satisfied. (There can be many for each function)

    • Level: define for each function/criteria what levels or expected performance or benchmark is acceptable to satisfy the need. This can come from an existing performance level, or from an objective to be reached.

    • Flexibility: Establish the negotiability of the level.

Function/Need Deliverable Criteria Target Level Flexibility
Procure Goods and Services Award of Service Provider Contracts # of Contracts Awarded in Fiscal Year 95% of contracts awarded ±5% of contracts
Maintain Traffic on Ramp E-N Traffic flow during morning rush hour % of rush hour traffic accommodated 100% of traffic accommodated F0 (no flexibility acceptable)

Who is involved in a Functional Performance Specification Technique workshop?

  • A facilitator with expertise in Functional Performance Specification technique leads the workshop.
  • Clients including the business area directly affected by the business process, product, or organization
  • Stakeholders who interact with the business process,
  • Individuals from outside the organization who might share similar business needs.

Is there a difference between the FAST Technique and the FPS Technique?

The FAST Technique aids the team in reaching consensus on their understanding of the project. The abstraction gained by looking at the project in terms of functions is used in the next phase, the creative phase, of the value analysis study.

The FPS Technique is used to define the project objectives by characterizing the performance requirements for certain functions. There is usually a systematic effort put into identifying researching the needs or functions using the FPS technique. The FPS Technique may be used only to define and document the product, service or project needs. Owners often use the document created during the FPS technique as input into a request for proposal or specification.

The type of functional diagram developed when using the FPS technique is sometimes termed a “functional tree”. European Standard BS EN 16271

To Learn More: Functional Performance Specification Summary
Publications >VA in Depth (Advanced VM) > Functional Performance Specification (FPS)

Information Phase Function Analysis Phase Creative Phase Evaluation Phase Development Phase Presentation Phase