Nigel S., Chambers S., Johnson R. Operations Management
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Reducing design complexity
Simplicity is usually seen as a virtue amongst designers of products and services. The most
elegant design solutions are often the simplest. However, when an operation produces a
variety of products or services (as most do) the range of products and services considered as
a whole can become complex, which, in turn, increases costs. Designers adopt a number of
approaches to reducing the inherent complexity in the design of their product or service range.
Here we describe three common approaches to complexity reduction – standardization,
commonality and modularization.
Standardization
Operations sometimes attempt to overcome the cost penalties of high variety by standardizing
their products, services or processes. This allows them to restrict variety to that which has
real value for the end-customer. Often it is the operation’s outputs which are standardized.
Examples of this are fast-food restaurants, discount supermarkets and telephone-based
insurance companies. Perhaps the most common example of standardization is the clothes
which most of us buy. Although everybody’s body shape is different, garment manufacturers
produce clothes in only a limited number of sizes. The range of sizes is chosen to give a
reasonable fit for most body shapes. To suit all their potential customers and/or to ensure
a perfect fit, garment manufacturers would have to provide an infeasibly large range of sizes.
Alternatively, they would need to provide a customized service. Both solutions would have a
significant impact on cost. This control of variety is an important issue with most companies.
A danger facing established operations is that they allow variety to grow excessively. They
are then faced with the task of variety reduction, often by assessing the real profit or con-
tribution of each product or service. Many organizations have significantly improved their
profitability by careful variety reduction. In order to overcome loss of business, customers
may be offered alternative products or services which provide similar value.
Commonality
Using common elements within a product or service can also simplify design complexity.
Using the same components across a range of automobiles is a common practice. Likewise,
standardizing the format of information inputs to a process can be achieved by using appro-
priately designed forms or screen formats. The more different products and services can be
based on common components, the less complex it is to produce them. For example, the
European aircraft maker Airbus has designed its new generation of jetliners with a high
degree of commonality. Airbus developed full design and operational commonality with the
introduction of fly-by-wire technology on its civil aircraft in the late 1980s. This meant that
ten aircraft models ranging from the 100-seat A318 through to the world’s largest aircraft, the
555-seat A380, feature virtually identical flight decks, common systems and similar handling
characteristics. In some cases, such as the entire A320 family, the aircraft even share the same
‘pilot-type rating’, which enables pilots with a single licence to fly any of them. The advantages
of commonality for the airline operators include a much shorter training time for pilots and
engineers when they move from one aircraft to another. This offers pilots the possibility of
flying a wide range of routes from short-haul to ultra-long-haul and leads to greater efficiencies
because common maintenance procedures can be designed with maintenance teams capable of
servicing any aircraft in the same family. Also, when up to 90 per cent of all parts are common
within a range of aircraft, there is a reduced need to carry a wide range of spare parts.
Modularization
The use of modular design principles involves designing standardized ‘sub-components’ of a
product or service which can be put together in different ways. It is possible to create wide choice
through the fully interchangeable assembly of various combinations of a smaller number of
standard sub-assemblies; computers are designed in this way, for example. These standardized
modules, or sub-assemblies, can be produced in higher volume, thereby reducing their cost.
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Standardization
Commonality
Modularization
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Similarly, the package holiday industry can assemble holidays to meet a specific customer
requirement, from pre-designed and purchased air travel, accommodation, insurance, and so
on. In education also there is an increasing use of modular courses which allow ‘customers’
choice but permit each module to have economical volumes of students. The short case
‘Customizing for kids’ describes an example of modularization in TV programme production.
Define the process to create the package
The product/service structure and bill-of-materials specifies what goes into a product. It
is around this stage in the design process where it is necessary to examine how a process
could put together the various components to create the final product or service. At one time
this activity would have been delayed until the very end of the design process. However, this
can cause problems if the designed product or service cannot be produced to the required
quality and cost constraints. For now, what is important to understand is that processes
should at least be examined in outline well before any product or service design is finalized.
We outlined some of the basic ideas behind process design. The techniques of process
mapping (see Chapter 4) can be used during this stage.
Design evaluation and improvement
The purpose of this stage in the design activity is to take the preliminary design and see if
it can be improved before the product or service is tested in the market. There are a number
of techniques that can be employed at this stage to evaluate and improve the preliminary
design. Here we treat three which have proved particularly useful:
● Quality function deployment (QFD)
● Value engineering (VE)
● Taguchi methods.
Quality function deployment
8
The key purpose of quality function deployment (QFD) is to try to ensure that the eventual
design of a product or service actually meets the needs of its customers. Customers may
not have been considered explicitly since the concept generation stage, and therefore it is
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Reducing design complexity is a principle that applies
just as much to service as to manufactured products.
For example, television programmes are made
increasingly with a worldwide market in mind. However,
most television audiences around the world have a
distinct preference for programmes which respect their
regional tastes, culture and of course language. The
challenge facing global programme makers therefore
is to try and achieve the economies which come as
a result of high volume production while allowing
programmes to be customized for different markets.
For example, take the programme Art Attack! made for
the Disney Channel, a children’s TV channel shown
around the world. In 2001 two hundred and sixteen
Short case
Customizing for kids
7
episodes of the show were made in six different language
versions. About 60 per cent of each show is common
across all versions. Shots without speaking or where
the presenter’s face is not visible are shot separately.
For example, if a simple cardboard model is being made
all versions will share the scenes where the presenter’s
hands only are visible. Commentary in the appropriate
language is over-dubbed onto the scenes which are
edited seamlessly with other shots of the appropriate
presenter. The final product will have the head and
shoulders of Brazilian, French, Italian, German, or
Spanish presenters flawlessly mixed with the same pair
of (British) hands constructing the model. The result is
that local viewers in each market see the show as their
own. Even though presenters are flown into the UK
production studies, the cost of making each episode is
only about one third of producing separate programmes
for each market.
Quality function
deployment
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appropriate to check that what is being proposed for the design of the product or service
will meet their needs. It is a technique that was developed in Japan at Mitsubishi’s Kobe
shipyard and used extensively by Toyota, the motor vehicle manufacturer, and its suppliers.
It is also known as the ‘house of quality’ (because of its shape) and the ‘voice of the customer’
(because of its purpose). The technique tries to capture what the customer needs and how it
might be achieved. Figure 5.7 shows an example of quality function deployment being used
in the design of a new information system product. The QFD matrix is a formal articulation
of how the company sees the relationship between the requirements of the customer (the
whats) and the design characteristics of the new product (the hows). The matrix contains
various sections, as explained below:
● The whats, or ‘customer requirements’, is the list of competitive factors which customers
find significant. Their relative importance is scored, in this case on a 10-point scale, with
accurate scoring the highest.
● The competitive scores indicate the relative performance of the product, in this case on a
1 to 5 scale. Also indicated are the performances of two competitor products.
● The hows, or ‘design characteristics’ of the product, are the various ‘dimensions’ of the
design which will operationalize customer requirements within the product or service.
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Figure 5.7 A QFD matrix for an information system product
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● The central matrix (sometimes called the ‘relationship matrix’) represents a view of the
interrelationship between the whats and the hows. This is often based on value judgements
made by the design team. The symbols indicate the strength of the relationship – for
example, the relationship between the ability to link remotely to the system and the intranet
compatibility of the product is strong. All the relationships are studied, but in many cases,
where the cell of the matrix is blank, there is none.
● The bottom box of the matrix is a technical assessment of the product. This contains the
absolute importance of each design characteristic. [For example, the design characteristic
‘interfaces’ has a relative importance of (9 × 5) + (1 × 9) = 54.] This is also translated into
a ranked relative importance. In addition, the degree of technical difficulty to achieve high
levels of performance in each design characteristic is indicated on a 1 to 5 scale.
● The triangular ‘roof ’ of the ‘house’ captures any information the team has about the
correlations (positive or negative) between the various design characteristics.
Although the details of QFD may vary between its different variants, the principle is generally
common, namely to identify the customer requirements for a product or service (together with
their relative importance) and to relate them to the design characteristics which translate those
requirements into practice. In fact, this principle can be continued by making the hows from
one stage become the whats of the next (see Fig. 5.8). Some experienced users of QFD have
up to four linked matrices in this way. If engineering or process trade-offs need to be made at
a later stage, the interrelated houses enable the effect on customer requirements to be determined.
Value engineering
The purpose of value engineering is to try to reduce costs, and prevent any unnecessary
costs, before producing the product or service. Simply put, it tries to eliminate any costs that
do not contribute to the value and performance of the product or service. (‘Value analysis’
is the name given to the same process when it is concerned with cost reduction after the
product or service has been introduced.) Value-engineering programmes are usually con-
ducted by project teams consisting of designers, purchasing specialists, operations managers
and financial analysts. The chosen elements of the package are subject to rigorous scrutiny,
by analysing their function and cost, then trying to find any similar components that could
do the same job at lower cost. The team may attempt to reduce the number of components,
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Figure 5.8 QFD matrices can be linked with the ‘hows’ of one matrix forming the ‘whats’ of the next
Value engineering
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or use cheaper materials, or simplify processes. For example, Motorola used value engineering
to reduce the number of parts in its mobile phones from ‘thousands’ down to ‘hundreds’ and
even less, with a drastic reduction in processing time and cost.
Value engineering requires innovative and critical thinking, but it is also carried out using
a formal procedure. The procedure examines the purpose of the product or service, its basic
functions and its secondary functions. Taking the example of the remote mouse used previously:
● The purpose of the remote mouse is to communicate with the computer.
● The basic function is to control presentation slide shows.
● The secondary function is to be plug-and-play-compatible with any system.
Team members would then propose ways to improve the secondary functions by combining,
revising or eliminating them. All ideas would then be checked for feasibility, acceptability,
vulnerability and their contribution to the value and purpose of the product or service.
Taguchi methods
The main purpose of Taguchi methods, as advocated by Genichi Taguchi,
9
is to test the
robustness of a design. The basis of the idea is that the product or service should still per-
form in extreme conditions. A telephone, for example, should still work even when it has
been knocked onto the floor. Although one does not expect customers to knock a telephone
to the floor, this does happen, and so the need to build strength into the casing should be
considered in its design. Likewise, a pizza parlour should be able to cope with a sudden
rush of customers and a hotel should be able to cope with early arrivals. Product and service
designers therefore need to brainstorm to try to identify all the possible situations that
might arise and check that the product or service is capable of dealing with those that are
deemed to be necessary and cost-effective. In the case of an adventure holiday, for example,
service designers need to plan for such contingencies as:
● foul weather – the need for bad-weather alternatives;
● equipment failure – the provision of enough equipment to cover for maintenance;
● staff shortages – flexible working to allow cover from one area to another;
● accidents – the ability to deal with an accident without jeopardizing the other children
in the group, with easily accessible first-aid equipment, and using facilities and equipment
that are easy to clean and unlikely to cause damage to children;
● illness – the ability to deal with ill children who are unable to take part in an activity.
The task is then to achieve a design which can cope with all these uncertainties. The major
problem designers face is that the number of design factors which they could vary to try
to cope with the uncertainties, when taken together, is very large. For example, in designing
the telephone casing there could be many thousands of combinations of casing size, casing
shape, casing thickness, materials, jointing methods, etc. Performing all the investigations
(or experiments, as they are called in the Taguchi technique) to try to find a combination
of design factors which gives an optimum design can be a lengthy process. The Taguchi
procedure is a statistical procedure for carrying out relatively few experiments while still
being able to determine the best combination of design factors. Here ‘best’ means the lowest
cost and the highest degree of uniformity.
Prototyping and final design
At around this stage in the design activity it is necessary to turn the improved design into
a prototype so that it can be tested. It may be too risky to go into full production of the
telephone, or the holiday, before testing it out, so it is usually more appropriate to create a
prototype. Product prototypes include everything from clay models to computer simulations.
Service prototypes may also include computer simulations but also the actual implementation
of the service on a pilot basis. Many retailing organizations pilot new products and services
in a small number of stores in order to test customers’ reaction to them. Increasingly, it is
Purpose
Basic functions
Secondary functions
Taguchi methods
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possible to store the data that define a product or service in a digital format on computer
systems, which allows this virtual prototype to be tested in much the same way as a physical
prototype. This is a familiar idea in some industries such as magazine publishing, where
images and text can be rearranged and subjected to scrutiny prior to them existing in any
physical form. This allows them to be amended right up to the point of production without
incurring high costs. Now this same principle is applied to the prototype stage in the design
of three-dimensional physical products and services. Virtual-reality-based simulations allow
businesses to test new products and services as well as visualize and plan the processes that
will produce them. Individual component parts can be positioned together virtually and tested
for fit or interference. Even virtual workers can be introduced into the prototyping system
to check for ease of assembly or operation.
Computer-aided design (CAD)
CAD systems provide the computer-aided ability to create and modify product drawings.
These systems allow conventionally used shapes such as points, lines, arcs, circles and text,
to be added to a computer-based representation of the product. Once incorporated into the
design, these entities can be copied, moved about, rotated through angles, magnified or deleted.
The designs thus created can be saved in the memory of the system and retrieved for later use.
This enables a library of standardized drawings of parts and components to be built up. The
simplest CAD systems model only in two dimensions in a similar way to a conventional
engineering ‘blueprint’. More sophisticated systems model products in three dimensions.
The most obvious advantage of CAD systems is that their ability to store and retrieve design
data quickly, as well as their ability to manipulate design details, can considerably increase the
productivity of the design activity. In addition to this, however, because changes can be made
rapidly to designs, CAD systems can considerably enhance the flexibility of the design activity,
enabling modifications to be made much more rapidly. Further, the use of standardized
libraries of shapes and entities can reduce the possibility of errors in the design.
Skunkworks
10
Encouraging creativity in design, while at the same time recognizing the constraints of
everyday business life, has always been one of the great challenges of industrial design. One
well-known approach to releasing the design and development creativity of a group has
been called a ‘Skunkworks’. This is usually taken to mean a small team who are taken out
of their normal work environment and granted freedom from their normal management
activities and constraints. It was an idea that originated in the Lockheed aircraft company in
the 1940s, where designers were set up outside the normal organizational structure and given
the task of designing a high-speed fighter plane. The experiment was so successful that the
company continued with it to develop other innovative products.
Since that time many other companies have used a similar approach, although ‘Skunkworks’
is a registered trademark of Lockheed Martin Corporation. Motorola’s mobile phone ‘Razr’
was designed and developed in a Skunkworks-like special laboratory that the company set
up, well away from its main Research and Development site in Illinois. Even the décor and
layout of the laboratory were different: open-plan and with lots of bright colours. Something
similar is reportedly used by Malaysia Airlines to tackle wider business issues, not just ‘design’
assignments.
The benefits of interactive design
Earlier we made the point that in practice it is a mistake to separate the design of products
and services from the design of the processes which will produce them. Operations managers
should have some involvement from the initial evaluation of the concept right through to the
Virtual prototype
CAD
Skunkworks
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production of the product or service and its introduction to the market. Merging the design
of products/services and the processes which create them is sometimes called interactive
design. Its benefits come from the reduction in the elapsed time for the whole design activity,
from concept through to market introduction. This is often called the time to market (TTM).
The argument in favour of reducing time to market is that doing so gives increased com-
petitive advantage. For example, if it takes a company five years to develop a product from
concept to market, with a given set of resources, it can introduce a new product only once every
five years. If its rival can develop products in three years, it can introduce its new product,
together with its (presumably) improved performance, once every three years. This means
that the rival company does not have to make such radical improvements in performance each
time it introduces a new product, because it is introducing its new products more frequently.
In other words, shorter TTM means that companies get more opportunities to improve the
performance of their products or services.
If the development process takes longer than expected (or even worse, longer than com-
petitors’) two effects are likely to show. The first is that the costs of development will increase.
Having to use development resources, such as designers, technicians, subcontractors, and
so on, for a longer development period usually increases the costs of development. Perhaps
more seriously, the late introduction of the product or service will delay the revenue from
its sale (and possibly reduce the total revenue substantially if competitors have already got
to the market with their own products or services). The net effect of this could be not only
a considerable reduction in sales but also reduced profitability – an outcome which could
considerably extend the time before the company breaks even on its investment in the new
product or service. This is illustrated in Figure 5.9.
A number of factors have been suggested which can significantly reduce time to market
for a product or service, including the following:
● simultaneous development of the various stages in the overall process;
● an early resolution of design conflict and uncertainty;
● an organizational structure which reflects the development project.
Figure 5.9 Delay in the time to market of new products and services not only reduces and delays revenues, it also
increases the costs of development. The combination of both these effects usually delays the financial break-even
point far more than the delay in the time to market
Interactive design
Interactive design can
shorten time to market
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Simultaneous development
Earlier in the chapter we described the design process as essentially a set of individual,
predetermined stages. Sometimes one stage is completed before the next one commences.
This step-by-step, or sequential, approach has traditionally been the typical form of product/
service development. It has some advantages. It is easy to manage and control design pro-
jects organized in this way, since each stage is clearly defined. In addition, each stage is
completed before the next stage is begun, so each stage can focus its skills and expertise on
a limited set of tasks. The main problem of the sequential approach is that it is both time-
consuming and costly. When each stage is separate, with a clearly defined set of tasks, any
difficulties encountered during the design at one stage might necessitate the design being
halted while responsibility moves back to the previous stage. This sequential approach is
shown in Figure 5.10(a).
Yet often there is really little need to wait until the absolute finalization of one stage
before starting the next. For example, perhaps while generating the concept, the evaluation
activity of screening and selection could be started. It is likely that some concepts could be
judged as ‘non-starters’ relatively early on in the process of idea generation. Similarly, during
the screening stage, it is likely that some aspects of the design will become obvious before the
phase is finally complete. Therefore, the preliminary work on these parts of the design could
be commenced at that point. This principle can be taken right through all the stages, one stage
commencing before the previous one has finished, so there is simultaneous or concurrent
work on the stages (see Fig. 5.10(b)). (Note that simultaneous development is often called
simultaneous (or concurrent) engineering in manufacturing operations.)
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Figure 5.10 (a) Sequential arrangement of the stages in the design activity; (b) simultaneous
arrangement of the stages in the design activity
Sequential approach
to design
Simultaneous or
concurrent approach
to design
Simultaneous (or
concurrent) engineering
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Figure 5.11 Sorting out problems early saves greater disruption later in the design activity
Early conflict resolution
Characterizing the design activity as a whole series of decisions is a useful way of thinking about
design. However, a decision, once made, need not totally and utterly commit the organization.
For example, if a design team is designing a new vacuum cleaner, the decision to adopt a par-
ticular style and type of electric motor might have seemed sensible at the time the decision was
made but might have to be changed later, in the light of new information. It could be that
a new electric motor becomes available which is clearly superior to the one initially selected.
Under those circumstances the designers might very well want to change their decision.
There are other, more avoidable, reasons for designers changing their minds during the
design activity, however. Perhaps one of the initial design decisions was made without sufficient
discussion among those in the organization who have a valid contribution to make. It may
even be that when the decision was made there was insufficient agreement to formalize it, and
the design team decided to carry on without formally making the decision. Yet subsequent
decisions might be made as though the decision had been formalized. For example, suppose
the company could not agree on the correct size of electric motor to put into its vacuum
cleaner. It might well carry on with the rest of the design work while further discussions
and investigations take place on what kind of electric motor to incorporate in the design.
Yet much of the rest of the product’s design is likely to depend on the choice of the electric
motor. The plastic housings, the bearings, the sizes of various apertures, and so on, could
all be affected by this decision. Failure to resolve these conflicts and/or decisions early on in
the process can prolong the degree of uncertainty in the total design activity. In addition,
if a decision is made (even implicitly) and then changed later on in the process, the costs of
that change can be very large. However, if the design team manages to resolve conflict early
in the design activity, this will reduce the degree of uncertainty within the project and reduce
the extra cost and, most significantly, time associated with either managing this uncertainty
or changing decisions already made. Figure 5.11 illustrates two patterns of design changes
through the life of the total design, which imply different time-to-market performances.
Project-based organization structures
The total process of developing concepts through to market will almost certainly involve
personnel from several different areas of the organization. To continue the vacuum cleaner
example, it is likely that the vacuum cleaner company would involve staff from its research
and development department, engineering, production management, marketing and finance.
All these different functions will have some part to play in making the decisions which
will shape the final design. Yet any design project will also have an existence of its own. It
will have a project name, an individual manager or group of staff who are championing the
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project, a budget and, hopefully, a clear strategic purpose in the organization. The organ-
izational question is which of these two ideas – the various organizational functions which
contribute to the design or the design project itself – should dominate the way in which the
design activity is managed?
Before answering this, it is useful to look at the range of organizational structures which
are available – from pure functional to pure project forms. In a pure functional organization,
all staff associated with the design project are based unambiguously in their functional groups.
There is no project-based group at all. They may be working full-time on the project but all
communications and liaison are carried out through their functional manager. The project
exists because of agreement between these functional managers. At the other extreme, all the
individual members of staff from each function who are involved in the project could be
moved out of their functions and perhaps even physically relocated to a task force dedicated
solely to the project. The task force could be led by a project manager who might hold all the
budget allocated to the design project. Not all members of the task force necessarily have to
stay in the team throughout the development period, but a substantial core might see the
project through from start to finish. Some members of a design team may even be from other
companies. In between these two extremes there are various types of matrix organization
with varying emphasis on these two aspects of the organization (see Fig. 5.12). Although the
‘task force’ type of organization, especially for small projects, can sometimes be a little
cumbersome, it seems to be generally agreed that, for substantial projects at least, it is more
effective at reducing overall time to market.
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Figure 5.12 Organization structures for the design activity
Functional design
organization
Project design
organization
Task force
Matrix organization
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