Object-Oriented Analysis and Functional Specifications Oracle Database Tips by Donald Burleson

In order to properly describe the environment of an object-oriented system, the designer needs to be able to develop a conceptual framework.  Object-oriented systems view the world at a much higher level than traditional systems, and unlike traditional analysis, it is no longer necessary to de-partition systems down to the data element level.  Object-oriented databases view the system components as physical "objects" (i.e. order forms, invoices), rather than abstract data definitions. Figure 3.3 shows and order-form object that contains the Customer, Order and Item list objects that participate in the order form. 

Figure 3.3 A composite object and its object sub-objects

Each person sees the real world from a framework of their own personal experiences, and each person's conceptual framework determines how they look at the world around them.  Experienced systems individuals today are accustomed to viewing databases as being populated with rows, columns and fields.  The object-oriented database analyst must learn to view the world at a much higher level, viewing "objects" as consolidations of many columns and rows, thereby doing a much better job at modeling the real-world.

Conceptualization allows a person to look at an object and see new applications for it. This "conceptual reversal" is used by many creative thinkers when they come up with novel uses for existing principles.  For example, many people today look at an empty soda pop bottle and just see something to be recycled, while others look at it and see a possible bird feeder, vase or plant holder.

Concepts allow us to develop recognition about the classification of objects.  For example, most people use the concept of "wings" to classify airplanes, and the concept of "hull" to identify ships.  But what happens when an object such as the Alberta Clipper, the famous seaplane, crosses the conceptual boundaries of two object classes?    Sharing characteristics from two concepts, the Alberta Clipper inherits the behaviors and attributes of both aircraft and ships.

It is important to realize that concepts are not required to have any physical existence.  Object-oriented systems allow for the use of "abstract" or intangible classes which do not have any concrete objects.  The idea of conceptualization can be directly applied to object-oriented database analysis.  The primary goal of object-oriented database analysis is to identify the behaviors, some of which may be abstract and the data that may be non-quantifiable.  If the goal of object-oriented databases is to closely model the real world, then both concrete and abstract data as well as behaviors must be accounted for in the database analysis.

Object-oriented analysis (OOA) requires the designer to identify the relevant entities, all relationships between these entities, and a generalization hierarchy which decomposes the entities into subclasses.  This involves developing a conceptual framework for the system; the perception of the system analyst can have a immense impact on the final design.

In a traditional systems development project, a structured specification is prepared to logically describe the hierarchy of processes, the data flowing between processes, and the functionality of each process.  The structured specification document provides a complete identification of the system components from a logical perspective.

Object-oriented analysis has the goal of delineating the objects, determining the relationships between the objects, and understanding the behaviors of each object.  Whereas a traditional analysis is focused on the transformation of data, object-oriented analysis has a focus on the encapsulation of objects behaviors and the interactions between the objects.  This method is an extension of traditional analysis techniques, and begins with a structured specification.

 

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