13-03-2014, 03:58 PM
History of UML: Methods and Notations
Methods and Notations.docx (Size: 119.73 KB / Downloads: 14)
In its short history, information technology has already produced a plethora of methods and notations. We have methods and notations for design, structure, processing, and storage of information. We also have methods for the planning, modeling, implementation, assembly, testing, documentation, adjustment, etc. of systems. Some of the concepts used are relatively fundamental, and because of that, they can also be found beyond the field of information technology. One example of that is inheritance, which is present in nature, but is also a cornerstone of object-oriented programming.
Until about the 1970s, software developers viewed the development of software as an artistic venture. But because systems became more and more complex, software development and maintenance could no longer be conquered with this creative-individual approach. Eventually, this approach led to the software crisis.
This crisis leads to the engineering approach (software engineering) and structured programming. Methods were developed for the structuring of systems and for the processes of design, development, and maintenance. Process-oriented approaches, for example the Hierarchy Input Processing Output (HIPO) method, emphasized the functionality of systems. With this method the total system is divided into smaller components through functional decomposition.
Figure 2.10 gives a visual overview (hierarchical diagram) of the sub-functions in the invoice example. An input-process-output schema describes every functional element.
At the same time, data-structure oriented approaches were developed, such as the Jackson method, in which the program structure is derived from the graphical display of data structures.