posted 11 years ago
Hi Radek. Welcome to the Ranch!
Well, this would be my take on it. Requirements analysis describes the activities of understanding the stated requirements to make sure they are clear and understood by everyone (and, importantly, everyone understand the same thing!). So it's all about understanding what the problem to be solved is.
Structured analysis and OO analysis are specific approaches to analysis, designed to be suitable for a particular development approach. Both involve creating models to describe the problem domain. But they differ in terms of the types of models that are produced. Structured Analysis was the more traditional approach, but with the adoption of OO languages new approaches to the modelling were developed that fitted in better. So OO analysis involves modelling the problem domain with classes - you produce class diagrams and descriptions - and this produces a model that is then refined in the following phases. So the classes and relationships you identify in the analysis phase will provide the core domain classes for your code.
