\section{The Weight of an Architecture; Architectural Chaos or Bureaucratic Control?}
\label{sec:LWAarchitectureWeight}

Does an architecture help to be successfull in the business or does it harm the success?
As always the answer from the architect is: it depends. The crucial success factor is the weight
of the architecture.

\FigureImposeWidth{LWAarchitectureWeight}{Architecture Weight}{.8\textwidth}

Figure~\ref{fig:LWAarchitectureWeight} gives a definition for the weight of the architecture.
The simple definition is that the overall weight of an architecture is the sum of the weight of all rules
which together form the architecture.

The weight of a single rule is determined by {\it level of enforcement},
{\it scope (impact)}, {\it size}, {\it level of coupling or number of dependencies}.
Figure~\ref{fig:LWAarchitectureWeight} gives for each of these parameters
a scale from low weight to high weight.

\FigureImposeWidth{LWAarchitectureScope}{Scope and Impact}{.4\textwidth}

Figure~\ref{fig:LWAarchitectureScope} zooms in on the scope parameter to
make clear the relation between the scope of the rule and the consequence for the weight.

For instance a rule like:
{\it all the functions in all the products of the portfolio
must (manadatory) return an complete predefined status object as defined in the system design specification,
chapter exception handling, making use of the template as described in the coding standards
and using the prescribed class and include files as present in the appropriate version
of the code repository} is a heavy rule (mandatory, portfolio scope, 4 lines of text (without the appropriate
references) and depending on other entities {\it(system design spec, template and code standard, prescribed
classes and includes, repository)}.

\FigureImposeWidth{LWAstakeholdersArchitecture}{Criteria for an Architecture}{.6\textwidth}

So far no judgement is provided for having a {\it good} or {\it bad} architecture.
In order to make a judgement we need to understand the objectives and concerns of the stakeholders.
Figure~\ref{fig:LWAstakeholdersArchitecture} shows a number of the stakeholders and their
main concerns.
Note that the stakeholders have different and sometimes conflicting requirements, such is life.

\FigureImposeWidth{LWAeffectivenessCurves}{Weight versus Effectiveness}{.6\textwidth}

The next step in reaching a judgement is to look at the relation between effectiveness and weight.
Figure~\ref{fig:LWAeffectivenessCurves} show this relationship for
flexibility (evolution, responsiveness, maintenance) and manageability
(integration, interoperability, providing control).
Flexibility decreases when the weight increases, while the manageability is proportional with the weight.

\FigureImposeWidth{LWAeffectiveness}{Conclusion Part 2}{.6\textwidth}

The question of good of bad depends on the relative importance of flexibility and manageability.
For our dynamic markets and fast moving technology flexibility is very important,
but for customer satisfaction the manageability is also important.
The combination of these 2 requirements is shown in figure~\ref{fig:LWAeffectiveness}, where
the curve shows that an optimum is achieved when both concerns are sufficiently met.

For different product/market/technology combinations different curves will result.
Mature (stable, certain) markets with slow changing technologies, the optimum is determined by
manageability and hence a heavy architecture. At the other extreme very dynamic markets and technologies,
with forgiving customers or low economic risks will benefit from extreme flexibility
and a very light architecture.

