EVALUATE & DECIDEThis section contains methods that can help you to evaluate design proposals
and make decisions while designing.
INTERACTION PROTOTYPING & EVALUATION
PRODUCT USABILITY EVALUATION
PRODUCT CONCEPT EVALUATION
EMOTION MEASUREMENT INSTRUMENT (PREMO)
EVR DECISION MATRIX
ITEMISED RESPONSE & PMI
COST PRICE ESTIMATION
REFERENCES & FURTHER READING: Harris, J.S., 1961. New Product Profile Chart. Chemical and Engineering News, 17 April, 39(16),
pp.110-118. / Roozenburg, N.F.M. and Eekels, J.*, 1995. Product Design: Fundamentals and Methods. Utrecht: Lemma.
When can the method be used?
A Harris Profile is based on the design
requirements for your design. Whenever
a number of alternative product concepts
need to be compared and evaluated, the
Harris Profile can be used to make your
– or your team’s – evaluation explicit. As
designers make some of their evaluations
intuitively, the Harris Profile can help
you to make those intuitions explicit so
that you can discuss them with other
A Harris Profile can be useful during
each phase of the design process, but
typically it is used after an idea generation
phase when ideas or concepts need to be
How to use the method?
Create a Harris Profile for each alternative
design concept. A Harris Profile consists of
an assessment of how the concept meets
each of the listed design requirements.
The evaluations are relative, comparing
the different concepts in terms of their
performance in each criterion. A four-
point scale is typically used to score
the concepts. You should interpret the
meaning of the scale positions:
-2 = bad, -1 = moderate, et cetera. Thanks
to the visual representation, decision
makers can quickly view the overall
score of each design alternative for all
the criteria, and compare them easily.
An important role of the Harris Profile
is to make your evaluation explicit
and easy to understand: it can help to
stimulate discussion with your project’s
stakeholders in the early phases of
design, when design requirements
typically change as the concepts
evolve and you gain a greater shared
understanding of the design problem.
List the design requirements as fully as
possible and rank them according to
their importance for the design project.
Create a four-point scale matrix next to
each requirement, coded -2, -1, +1, and
Create a Harris Profile for each of the
design alternatives by evaluating the
relative performance of each alternative
with respect to the requirements.
Draw the profile by marking the scores
in the four-point scale matrix for all the
Present the profiles next to each other to
allow discussion with stakeholders and to
determine which design concept has the
best overall score.
Limitations of the method
• The four-point scales should be
interpreted differently for each
requirement and are not necessarily
• It is tempting to interpret Harris
Profiles as ‘true’ representations of the
performance of design alternatives.
However, it is important to realise
that the performance assessment of
design concepts is typically an intuitive
prediction of performance, with low
• The primary function of the profile is to
communicate the evaluations that you
have made after careful discussions and
deliberations, and if necessary to open
up discussion to sharpen the definitions
of requirements or improve design
Tips & Concerns
• Use drawings to represent concepts
in each profile – this will enhance the
communicability of your profiles.
• If possible, cluster the criteria.
• Design is not a linear process, so you
might discover new design requirements
while evaluating concepts. You can
add those requirements to your Harris
Profile and enhance the accuracy of your
• When attributing the -2 or +2 values
to a criterion, be sure to colour all
the blocks in the Harris Profile. Only
then can you create a quick visual
overview of the overall score of a design
A Harris Profile is a graphic representation of the
strengths and weaknesses of design concepts with respect
to predefined design requirements. It is used to evaluate
design concepts and facilitate decisions on which
concepts to continue with in a design process.
In a Harris profile, the main design requirements are ranked in order of importance with the most important one on top. An
even number of possible scores are used to prevent neutral scoring. This way of evaluating is helpful when ideas and designs
are still conceptual and not worked out in detail: imagine the black squares are building blocks of a tower. By viewing ‘which
way the tower of blocks would fall’, a choice can be made. Colours should not be used and scores can not be added up. In
general, all decision making methods are meant to initiate discussion within the development team and to structure the
process of chosing. In the lower example, another design prevails because the design requirements are listed in another order.
It shows how another team could have a different view on what is important.
D E L F T D E S I G N G U I D E — 1 3 9 EVALUATE & DECIDE
REFERENCES & FURTHER READING: Roozenburg, N.F.M. and Eekels, J.*, 1995. Product Design: Fundamentals and Methods. Utrecht:
Lemma. / Roozenburg, N.F.M. and Eekels, J.*, 1998. Product Ontwerpen: Structuur en Methoden. 2nd ed. Utrecht: Lemma.
When can the method be used?
The Weighted Objectives Method is best
used when a decision has to be made
between a selected number of design
alternatives, design concepts or principal
solutions. Usually, the Weighted Objectives
Method is used when evaluating design
concepts, and to make a decision as to
which design concept should be developed
into a detailed design. The Weighted
Objectives Method enables you to sum up
the scores of all criteria into a numerical
value for each design alternative.
How to use the method?
The Weighted Objective Method assigns
scores to the degree to which a design
alternative satisfies a criterion. However, the
criteria that are used to evaluate the design
alternatives might differ in their importance.
For example, the cost price might be of
less importance than appealing aesthetics.
The Weighted Objectives Method allows
you to take into account the difference in
importance between criteria by assigning
weights according to their importance for
the evaluation. You can rank each of the
weights on a scale from 1 to 5 or decide on a
total sum of the weights of the criteria, for
Select the criteria according to which the
selection will be made.
Choose three to five concepts for
Assign weights to the criteria.
Construct a matrix, with the criteria in
rows and the concepts in columns.
Attribute values to how each concept
meets a criterion. Rank the scores of the
concepts from 1 to 10.
Calculate the overall score of each concept
by summing up the scores on each
criterion (make sure you take into account
the weight factor).
The concept with the highest score is the
Tips & Concerns
• This method should be carried out
coherently, while discussing and
reviewing both the weights assigned
to the criteria and the scores of the
concepts according to all the criteria.
• To determine the weight factors of
the criteria it is recommended that
you compare the criteria in pairs to
attribute a weight factor to each of
The Weighted Objectives Method is an evaluation method
for comparing design concepts based on the overall
value of each design concept.
From left to right: paperclip lamp, paperclip alphabet, staple city.
D E L F T D E S I G N G U I D E — 1 5 1 EVALUATE & DECIDE
By attributing weight factors to design requirements, the choice of a certain design can be precisely motivated. Design proposals
should be worked out in detail so that they can be scored. Like all methods for evaluation, the main aim is to initiate a structured
discussion and to communicate the processes of choice within a development team. The highest-scoring proposal is not necessarily
the winner. By analysing the scores, strong features of different proposals can be combined into a new one.