Shlaer–Mellor method

What makes Shlaer–Mellor unique among the object-oriented methods is: The general solution taken by the object-oriented analysis and design methods to these particular problems with structured analysis and design, was to switch from functional decomposition to semantic decomposition.

In current (2011) terminology, we would say the Shlaer–Mellor method uses a form of model-driven architecture (MDA) normally associated with the Unified Modeling Language (UML).

By taking this translative approach, the implementation is always generated (either manually, or more typically, automatically) directly from the analysis.

This is not to say that there is no design in Shlaer–Mellor, rather that there is considered to be a virtual machine that can execute any Shlaer–Mellor analysis model for any particular hardware/software platform combination.

[7] One of the requirements for automated code generation is to precisely model the actions within the finite-state machines used to express dynamic behaviour of Shlaer–Mellor objects.

Shlaer–Mellor is unique amongst object-oriented analysis methods in expressing such sequential behavior graphically as Action Data Flow Diagrams (ADFDs).

Whilst functionality heavily dependent upon timing constraints may be difficult to test, the majority of system behaviour is highly predictable due to the prioritized execution model.

"[9] In line with comment Capretz (1996) argues that the Shlaer–Mellor method "fails to account for the vast majority of object-oriented ideas and an ordinary graphical notation is prescribed", which is primarily taken "from entity–relationship diagrams and data flow diagrams found in other structured methods".