Simply put - this could be a plan or description on how to go about building the information system. Going a level deeper, it can be seen as a logical or abstract way of representing the Information system. The techniques of modeling have evolved over time from flow charts, case tools and various Object oriented approaches leading to a vendor independent modeling language and standard.
Although modeling is a very crucial step towards building robust and complex systems, it is not the only "cure" or "silver bullet" to achieve 100% robust and complex systems.
In fact none of components of Information systems - people, processes or technologies put together are a complete, perfect formula to achieve 100% satisfaction for Systems Development. It is a matter of perception.
Take the case of UML. It is a unified modeling language. The concept is not new. The standard modeling language is supposed to enable engineers and architects represent their models better linking their models to the software implementation. It is a step intended to be automated towards builing Information systems. Model is based on software in the case of software systems. That is the uniqueness of software. Model is not a physical hardware component. Modeled artifact is abstract, intangible and logical. This is the reason that models cannot be completely depended upon for accuracy in the deliverables.
I recommend reading some of the hilarious and amusing stories on "death by uml fever" for an idea of how things happen and what can be made out of technologies!
Understand the purpose of the tool. Watch the tool/ technology/ language grow. Use it with care and attention as to what works for you and what does not. Review and criticise it. Let those who ignore this basic human judgement know with freedom of opinion. Emphasise with proof.
They are supporting tools - just like a thermometer or a bloodpressure monitor. They are there to diagnose fever or monitor blood pressure, not a cure for all the patient's problems!
