\section{Examples of smartening fuzzy requirements}

The user or consumer needs are shown in figure~\ref{fig:FFTSuserNeeds}.
As shown in this figure none of these requirements is specific nor measurable et cetera.
However the qualified needs do provide insight in the motivation of users
and in that way are useful to help others to obtain a better understanding.

\FigureImposeWidth{FFTSuserNeeds}{The ''Fuzzy'' needs of the User}{.8\textwidth}

Figure~\ref{fig:FFTSproviderNeeds} shows in the same way the fuzzy needs of the providers
and the retailers, which are also stakeholders of these products.

\FigureImposeWidth{FFTSproviderNeeds}{The ''Fuzzy'' needs of the Provider}{.8\textwidth}

The world of the designers is much less fuzzy. Systems are decomposed and interfaces
are defined in SMART terms. Figure~\ref{fig:FFTSstandardInteractiveSystem} shows
the decomposition for this kind of product.

\FigureImposeWidth{FFTSstandardInteractiveSystem}{The ''SMART'' world of the Design}
{.5\textwidth}

In such a decomposition many specification items can be defined.
Figure~\ref{fig:FFTSstandardInteractiveSystemAnnotated} shows the decomposition annotated
with specification items. Also a typical flow is shown for some user interaction:
some request enters via the user interface, flows through al the blocks to the
relevant service, and the answer travels in the opposite way.
As an example we will have a look at the performance in terms of the response time.

\FigureImposeWidth{FFTSstandardInteractiveSystemAnnotated}{Specifiable characteristics}
{.8\textwidth}

All functions in the chain contribute to the response time,
figure~\ref{fig:FFTSlatencyBudget} shows an (academic) budget for this
response time. Note that the top part of the budget is well defined and in control
of the appliance designer, however the lower levels of the budget are
assumptions made by the appliance designer about the context.
The wider the context becomes the more uncertainty will be present in the numbers.

\FigureImposeWidth{FFTSlatencyBudget}{Response Time: Latency Budget}{.7\textwidth}

The designer of the appliance need to make assumptions about the context in order to make
a good design. These assumptions will be based on a model of the context.
Such a model can be calibrated by measuring the context for as far as it exists already.
However the designer should stay aware (as with all of his models) that this model
is a tremendous simplification of reality. Reality is infinitely complex
due to the possible variations in the food chain and the dynamics (changes over time).

One of the important characteristics for the user of the appliance is the response time.
As shown in figure~\ref{fig:FFTStotalChainResponseTime} the model indicates good
response times for functionality which stays within the appliance, but poor response times
for functions which need interaction with far away servers. This insight will influence
a lot of specification and design decisions. For all functions which require true
interactive responses (i.e. less than 200 ms), some local solution is required, maybe
supported by all kind of clever tricks such as look ahead, caching et cetera.

\FigureImposeWidth{FFTStotalChainResponseTime}{Interaction or Irritation?}{.8\textwidth}

A different area of fuzzy needs is image quality. The user needs good (sharp, bright,
smooth moving) image quality. The verifiable image quality is often based on synthetic
images, which enable verification for all technical parameters. However a perfect technical
image quality does not mean a satisfied user...

Some of the image quality aspects are even more fuzzy, for instance when perception
is taken into account (color blind people!), or worse when taste comes into play
(this image is too sharp, while someone else finds it too smooth).

Figure~\ref{fig:FFTSimageQuality} visualizes these different types of needs.
 
\FigureImposeWidth{FFTSimageQuality}{Image Quality}{.5\textwidth}

Fashion is also an intangible need of the user. However some product functions can be created
to make it possible to follow the fashion, for instance by enabling personalization. A well
known example is the exchangeable front of GSM phones.
Figure~\ref{fig:FFTSthemes} shows downloadable themes as example, which requires all kinds of
functions such as format, download, import, scale et cetera.

\FigureImposeWidth{FFTSthemes}{Fashionable}{.6\textwidth}

