Clarifying Objectives

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Design Process Overview What drives design?

Design process has seven distinct phases

The end goal

Product that customers WANT



Clarifying objectives: Objectives tree

Aim: to clarify design objectives

and sub-objectives, and therelationships between them.

Establishing functions : Function analysis

Aim: to establish the functions

required, and the systemboundary, of a new design.

Setting requirements : Performance specification

Aim: to make an accurate

specification of the performance

required of a design solution.



Determining : Quality function deployment

characteristics Aim: to set targets to be

achieved for the engineering

characteristics of a product, such

that they satisfy customer

requirements.

Generating alternatives : Morphological chart Aim : to generate the complete

range of alternative design

solutions for a product, and hence

to widen search for potential newsolution



Evaluating : Weighted objectives

alternatives Aim: to compare the utility values

of alternative design proposals,

on the basis of performance against

differentially weighted objectives.

Improving details : Value engineering

Aim: to increase or maintain the value of a product to its purchaser

while reducing its cost to its

producer.



Clarifying objectives

The starting point for a design is therefore very often an ill-defined problem.

Yet the designer must have some objectives to worktowards.

The outcome of designing is a proposal for some means toachieve a desired end. That end is the set of objectives thatthe designed object must meet.



What’s the Objective?

Objectives (or goals) are expressions of the desiredattributes and behaviors that the client wants to see in theproduct

Objectives are

‘Be’ words

They are qualities the object should have

So, designers task is to uncover the objectives of a designproject



An important first step in designing therefore is to try to

clarify the design objectives.

Objectives may change, expand , contract or be completely altered as problem becomes better understood and as

solution ideas develop.

Objective statements are in such a form that they are easily understood by design team



The Objectives Tree Method offers a clear and useful format for such a statement of

objectives. shows the objectives and the general means.

diagrammatic form.

How objectives are related to each other.

hierarchical pattern of objectives and sub-objectives.

Make vague statements more specific by asking: What is meant by that statement?

Other useful questions to ask when expanding andclarifying design objectives: Why? How? What?



Objectives Tree Method (2)

Three step procedure:

Prepare a list of design objectives

Order the list into sets of higher-level and lower-level objectives

Draw a tree of objectives, showing hierarchicalrelationships and interconnections



Step 1: Listing the Objectives This can be done by:

Talking with (interviewing) your customer

Thoroughly reading any written design statements andrequirements

Brainstorming within your team

Take vague statements and make them clearer by asking“what is meant by this statement”



After the initial list is compiled, some things other thanobjectives may have slipped in

Constraints - restrictions or limitations on a behavior orsome aspect of a design

Functions - operations the design is supposed to do

Implementations - ways to execute the functions

Check if each statement is an objective Objectives are normally “being” statements

Try saying “an objective is to be [statement] ”

If it makes sense, then it’s most likely an objective

Objectives can also be written as “more (or less) of [thestatement] is better than less (or more) of [thestatement]”



Step 1 Active Experimentation

An objective for a m/c tool that it must be safe, might beexpanded to

low risk of injury to operator

low risk of operator mistakes

low risk of damage to work-piece or tool

automatic cut-out on overload

'why do we want to achieve this objective?','how can we achieve it'?.' and 'what implicit objectivesunderlie the stated ones?' or 'what is the problem really about?'



Step 2: Ordering the List

Group the statements into related topics using anaffinity diagram

Design

Objective



Copy design objectives to post-it® notes

Place one on a board

Compare next objective card to the first

If different, begin a new column

If similar intent, place under the first column

Repeat for all design objective cards

Result: Objectives sorted by similar statement

Within each column there may be levels of objectives

Lower-level objectives answer the question “How?”

Higher-level objectives answer the question “Why?”

Transform to a hierarchical list of objectives



Example:

SAFETY

machine must be safe

low risk of injury to operator

low risk of operator mistakes

low risk of damage to work-piece or tool

automatic cut-out on overload

'low risk of injury' might be considered more

important than 'low risk of mistakes', but allthree low risk objectives can conveniently

be grouped at about the same level.



The valuable aspect to sorting objectives roughly intolevels is that it encourages you to think more clearly about the objectives and about the relationshipsbetween means and ends. As you write out your lists inhierarchical levels, you will probably also continue toexpand them, as you think of further means to meetsub objectives to meet objectives, etc.



Step 3: Draw the Tree

From Step 2, you have a clustered set of objectives Notice that some of the objectives within a cluster

may be more specific than others

This implies a hierarchical nature to the objectives

The hierarchy (general to more specific) can berepresented in a graphical structure known as anobjectives tree



Step 3: Draw the Tree (2)

Consider the example objectives list and resulting treefor the design of a safe ladder:

The ladder should be safe

The ladder should be stable

Stable on floors and smooth surfaces

Stable on relatively level ground

The ladder should be reasonably stiff

The ladder should be marketable

The ladder should be useful

Useful indoors

Useful for electrical work

Useful for maintenance work

Useful outdoors

Be useful at the right height

The ladder should be relatively inexpensive

The ladder should be portable

Be light weight

Be small when ready for transport

The ladder should be durable




The Objectives Tree diagram looks like an “upside-down” tree The overall objective of the tree is at the top

Underneath it, branches break the objective intomore detailed objectives

Can have many levels and interconnections

As you move deeper into the

hierarchy, the objectives answer

the question “how is the above

objective met?”

As you move higher up in the

hierarchy, the objectives answer

the question “why are the below

objectives important?”




The objectives treediagram may alternatively bedrawn on its side

Example: Car door



Summary :

1. Prepare a list of design objectives. These are taken fromthe design brief, from questions to the client, and fromdiscussion in the design team.

2. Order the list into sets of higher-level and lower-level

objectives. The expanded list of objectives and subobjectives is grouped roughly into hierarchical levels.

3. Draw a diagrammatic tree of objectives, showinghierarchical relationships and interconnections. The

branches in the tree represent relationships whichsuggest means of achieving objectives.

Clarifying Objectives

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