Basic Concepts

The logic behind the functioning of the Classification Toolset is closely connected with several basic concepts referring mainly to the properties of repository objects and the nature of the classification process.

The main properties of repository objects (such as Person Responsible, Package and so on) are stored in the object directory (TADIR). The additional properties (such as Creation Date, Last Changed By and so on) are part of the metadata of the objects.

If you want to add new properties to a repository object, you need to extend either the object directory or the structure of the metadata. The advantages and disadvantages of this are:

Advantages	Disadvantages
The properties are available after each transport of the object into another system.	Storing new properties as metadata generates development overhead for extending tools in order to maintain the new property.
The properties are maintained in the course of the normal development process.	If the property covers different object types, you need to use several different tools to maintain it.
	The properties can be only be changed in the original system of the object.

The key to solving the above mentioned problems is to distinguish between functional and non-functional properties of repository objects.

The visibility of a class is a functional property because you need to know whether an attribute is private, protected or public in order to define the context in which the attribute value can be accessed.

The accessibility property can be regarded as non-functional because the information whether or not a screen is accessible is not needed by the GUI to display a screen.

It is possible to avoid the disadvantages of storing new properties as metadata by treating non-functional properties as separate repository objects. In that case, if you want to add new properties to a repository object, it is not necessary to extend the object directory or to change the development tools. It is also not mandatory for the new properties to have the same original system as the object they belong to.