The question : ''What is an architecture'' is addressed.
Trends in the customer world and in the technology are used to obtain an outline
of the product requirements. The customer world itself is a value chain
consisting of quite heterogeneous stakeholders.

To satisfy the needs of these customers an integral approach is required.
Architectures play a key role in such an integral approach.

Architecture lessons from practice are given to illustrate
criteria for a good architecture are discussed.
The concept of architecture-weight is introduced.
