\section{Challenges}
\label{sec:DYOFchallenges}

The world of high tech product development faces a number of challenges,
summarized in figure~\ref{fig:DYOFchallenges}.

\FigureImposeWidth{DYOFchallenges}{Hit list of challenges}{.7\textwidth}

\subsection{Market dynamics}

The market is changing continuously and the frequency of changes is high.
Figure~\ref{fig:DYOFmarketDynamics} shows several forces operating on the PMS market.

\FigureImposeWidth{DYOFmarketDynamics}{Market dynamics in medical}{.5\textwidth}

Companies from other domains are changing the playing field. 
Especially gen technology (early risk indication, preventive examination and therapy?),
pharmaceutics (focused and localized application of medicines) will change the clinical field quite a lot.

Information Technology suppliers and service providers, integrate all types
of information and applications in networks of systems.
This integration enables new applications and
also influences the conventional system boundaries and function allocations.

Government have a strong influence on the health care systems. Current trends are towards
cost reduction and cost control in attempt to keep health care provisions affordable for
the entire population. At the same time increased privacy awareness and concerns result in
new and more regulations, with far stretching consequences for most clinical systems.
The current threat of terrorism will also influence system requirements.

A global trend is an aging population, which has a considerable impact on the consumption of
clinical services. Also new diseases appear, which creates unforeseen needs.

The rapid advance in many technology areas (for example new materials,
miniaturization, new sensors, and  wireless) opens up many new possibilities.

\subsection{Interoperability}

Systems get more and more directly connected.
In the past humans linked the different systems together,
applying intelligence and adaptations were needed.
In the electronic age the adaptation must take place in the systems themselves.

\FigureImposeWidth{DYOFscopeOfInteroperability}{Interoperability: systems get connected at all levels}
{.7\textwidth}

Figure~\ref{fig:DYOFscopeOfInteroperability} shows that systems all levels in the hospital get connected.
Connectivity is not sufficient to justify the integration cost,
only if systems interoperate in a useful way true added value is created.

\FigureImposeWidth{DYOFmultiInteroperability}{Multi dimensional interoperability}{.7\textwidth}

An additional challenge for interoperability are the many dimensions in which interoperability is required,
as shown in figure~\ref{fig:DYOFmultiInteroperability}:
\settoheight{\myListItemsep}{.}
\begin{myList}
\item applications
\item languages, cultures
\item vendors
\item media, networks
\item standards
\item releases
\end{myList}

\subsection{Reliability}

The amount of software (and technology) in products is increasing exponentially,
as shown for televisions in figure~\ref{fig:LWAmooresLawRvO}.
Many other products show the same growth in the amount of software: Cardio Vascular X-ray systems,
MRI scanners, wafersteppers.

\FigureImposeWidth{LWAmooresLawRvO}{SW increase in televisions}{.7\textwidth}

Software is far from errorless. Studies of the density of errors in actual code show that
1000 lines of code typically contain 3 errors. In case of very good software processes and mature organizations
this figure is 1 a 2 errors per kloc, in poor organizations it can be much worse.

\FigureImposeWidth{DYOFreliability}{Increase of software threatens Reliability}{.7\textwidth}

Incremental increase of the code size will increase the number of hidden errors in a system also exponentially,
as shown in figure~\ref{fig:DYOFreliability}\footnote{Simple systems, which already contain fatal bugs
are appearing: for instance software vending machines, which need a power down when the software is crashed.}.

\subsection{Power consumption}

Many technological improvements show an exponential increase: circuit density, storage capacity,
processing power, network bandwidth. An exception is the energy density in batteries, which is improved, but
much less dramatically.
The power usage of processing per Watt has improved significantly, but unfortunately the
processing needs have increased also rapidly. Overall the power consumption of for instance PC's
is more or less constant.

\FigureImposeWidth{DYOFpower}{Power consumption and dissipation}{.7\textwidth}

Figure~\ref{fig:DYOFpower} shows these opposing forces: the need for less power consumption and for more
performance. There are multiple reasons to strive for less power consumption:
\begin{myList}
\item less heat dissipation, easier transport of waste heat
\item increase stand by time
\item increase operational time
\item decrease acoustic noise of cooling
\item decrease power supply cost
\end{myList}

Power consumption plays a role in all domains, for example in GSM phones (standby time,
operational time, wireless video), data centers (Amsterdam cannot accommodate more data centers,
due to the availability of electrical power), MRI gradients (faster switching of higher gradient fields,
amplifier costs, acoustics and cooling are significant technical challenge) and desktop PC's
(where a current trend is to silent fanless desktops).

\subsection{Security}

Several stakeholders have significant different security interests.
Figure~ref{fig:DYOFsecurity} shows 3 categories with different interest and security solutions:
\begin{myList}
\item Government and companies, which implement restrictive rules, which can be rather privacy intrusive
\item Consumers, who want to maintain privacy and at the same time usability of services\footnote{Which
can be quite conflicting. Who may have access to your medical data? Do you still want to control
this access in case of emergencies?}
\item The content industry, who want to get fair payment for content creation and distribution.
Their solution is again very restrictive, even violating the right of private copies, and characterized
by a paranoia attitude: every customer is assumed to be a criminal pirate.
\end{myList}

\FigureImposeWidth{DYOFsecurity}{Security conflicting interests}{.6\textwidth}

All stakeholders are confronted with threats: pirates,
thieves, terrorists, dictators, et cetera. The challenge is to find solutions which respect all the needs,
not only the needs of one of the stakeholders. Another challenge is to make systems sufficiently secure,
where a little bit insecure quickly means entirely insecure.
Last but not least is the human factor often the weakest link in the security chain.

\subsection{Creativity}

The rapid technology development has changed the nature of product creation challenges.
Several decades ago the main challenge was to get the desired performance at all;
Can we {\bf do} it? This shifted to the problem of realizing the performance within
practical constraints, such as cost, power and size; Can we {\bf make} it?

\FigureImposeWidth{DYOFcreativity}{Creativity as limiting factor}{.7\textwidth}

The next challenge was to create the product with large amounts of people in a limited amount of time.
Processes are a means to create products in large teams; Can we {\bf organize} it?
Today many well defined applications and services can be realized, the real
problem has shifted to which applications and functions are needed? Which services
can be used to sustain a business? Can we {\bf conceive} it?
