Expressing Functions: Verb-Noun Function Statements

Function analysis defines functions using:

A single active verb and a single descriptive noun.
The verb asserts a condition.
The noun defines.
Prevents preconceptions about what the solution should be.
Providing clarity about what the project must do, ensures 'all cost is for function' (Miles' central principle of function analysis)
A design feature which does not enable all the sought functionality, is simply adding cost and is reducing value and should not be present.
Due to difficulty of describing a function using a single verb/noun, some leeway is acceptable where complex functions require the use of more words.
This practice should be minimised as deviance from single verb/noun format risks biasing the designers towards a particular solution, reducing their ability to seek a solution which reflects the client's values.
Examples - Transmit light, maximise insulation, minimise vibration...

Function Types

Not all functions are considered equal in a function analysis. A functional hierarchy is formed to represent this.

Basic Function - Defines the purpose of the solution, often in the form of the project's mission statement. If the basic function isn't fulfilled, the design proposal is a failure.
Primary Functions - The basic function is enabled by several primary functions. A primary function can exist in it's own right.
Secondary Functions - Each primary function is often enabled by one or a few secondary functions.
Tertiary Functions - Some secondary functions may require tertiary functions to enable them, but suggests a lack of clarity or consensus among stakeholders in the function analysis.

Performing Function Analysis

Function analysis requires:

A method of eliciting functions.
A method of reviewing functions.
A method of organising and understanding functions.

Function analysis is a brainstorming activity involving a 2-step process:

First elicit possible functions, generally via a brainstorming exercise.
Then review and organise functions to 'make-sense' in a clear structure using FAST diagramming.

Identifying Functions

Each participant is given sticky notes.
The facilitator explains the verb-noun elicitation format.
The project problem is quickly reviewed to clarify its scope.
Participants are asked to individually note down all the functions they think the building needs to provide (in 15 minutes)
It is about quantity, not quality and are encouraged to not critique or filter their answers.
The facilitator then gathers the post-it notes and shuffle them into a randomly-ordered pile before undertaking the next stage which is Affinity Diagramming.

Affinity Diagramming

Process of stakeholders working together to group similar functions.
The post-it note at the top of the random pile is placed in the centre of the work surface.
The facilitator takes the next post-it note and reads aloud the function to ask the stakeholders how similar/dissimilar it is to the function on the surface.
Alternatively, stakeholders can hold on to their post-its and position it themselves; however, this approach limits the sense-making as some stakeholders will be unaware of discussions others have had.
If dissimilar, it is positioned further away; if similar, it is positioned close by; if exactly the same, it is placed on top.
Stakeholders should be encouraged to stand up as this stimulates engagement.
Once the functions have been placed and discussed, obvious clusters of related suggestions will emerge, with those closer sharing a stronger conceptual association.
Discussions build common understanding of the logic supporting the groups.
'Silence means yes' rule applies.
Before finishing, the facilitator asks stakeholders to review the emerging clusters and agree they are happy they make sense and if not, to move post-it notes and explain their rationale for doing so.
Once all stakeholders are happy with the arrangement, the affinity diagramming exercise concludes by the stakeholders discussing, agreeing and assigning meaning to each cluster and a name using a verb-noun pairing if possible to ensure they all share a common understanding of the clusters.
The verb-noun format provides the functions in the required format for the next stage of the process, FAST Diagramming.

Principles of F.A.S.T. Diagramming

Many different types.
This module focuses on the Customer F.A.S.T. diagram format.
A F.A.S.T. diagram organises the functions identified by function analysis into the primary, secondary and tertiary functions.
Essentially, FAST diagramming provides a simple representation of the client's functional expectations and stimulates social construction of common understanding between stakeholders.
It expresses requirements in purely functional terms to allow creative problem solving.
A FAST Diagram is self-validating and can be read in either direction.
Lower-order functions are positioned progressively right along the horizontal 'How?' axis.
Higher-order functions are positioned progressively left along the horizontal 'Why?' axis.
The vertical positioning of primary functions along the vertical needs vs. wants axis determines their importance.
The positioning of secondary functions to a primary function can tell designers whether the stakeholders consider those functions equally important in supporting the primary function.

Components of Customer F.A.S.T. Diagrams

Why? vs. How? axis.
Needs vs. Wants axis
Scope lines.
Functions organised into a hierarchy comprising of: one basic function, several primary functions, several secondary functions and a resource constraint line.

Why? vs. How? Axis

The horizontal axis.
Explains the relationship between the functions the project must perform by establishing a hierarchical relationship of functions.
Functions to the left are supported/facilitated/enabled by functions to the right.
If completed correctly, the diagram can be read in either direction along the axis - it is self-validating.

Needs vs. Wants

This is the vertical axis.
Designers need to know the stakeholders' priorities.
Stakeholders must determine which functions are needed and which are wanted.
Incorporating every function is unlikely as projects have finite resources (e.g. time and money)
Primary functions are ordered vertically by their importance to the stakeholders.
Functions positioned towards the top of the diagram are needed and those towards the bottom are wanted.
Positioning the functions begins to expose stakeholders' priorities which are a consequence of their values.

Scope Lines

Always 2 scope lines.
They define the content of the problem to be solved.
Anything left of the left scope line is the definition of the problem.
Anything to the right of the right scope line is the solution (or part of) to the problem.

	Creado por d.moran-10 hace más de 10 años

Undergraduate Value Management & Engineering Apunte sobre Function Analysis and FAST Diagramming, creado por d.moran-10 el 02/06/2014.