Object-orientation

What is the Object-orientation?

What is the Object-orientation? Let us think what is the object before we discuss the object-orientation.

What is the Object actually?

You may think the object is a thing we can see around us. Table, chair, computer, book, pen, clock and something else, they called object. Yes, you are right, anything we can see it even to touch it, it can be an object. Everything in your room, in your mind, is an object.

Coad and Yourdon (1990) define object as follows:

Object. An abstraction of something in a problem domain, reflecting the capabilities of the system to keep information about it, interact with it, or both.

A useful definition of abstraction in this context might be: 'A form of representation that includes only what is important or interesting from a particular view point'.

Object Definition

We define an object as a concept, abstraction, or thing with crisp boundaries and meaning for the problem at hand. Objects serve two purposes: The promote understanding of the real world and provide a practical basis for computer implementation.

What really is the object?

Booch (1994) summarizes the object that all objects in a model or in an information system have certain similarities to all other objects, that an object "has a state, a behavior and an identity".

Class and Object

Class is a concept that describes a set of objects that are specified in the same way. According to the UML specification, all objects of a given class share a common specification for their features, their semantics and the constraints upon them. (OMG, 2004c).

Instance is another word for a single object, but it also carries connotations of the class to which that object belongs: every object is an instance of some class. So, just like an object, an instance represents a single person, thing or concept in the application domain.

A class and its instances are related in the following manner. Each instance of a class is unique, just as every living person is unique, however closely they resemble someone else. This is true even when two instances have identical characteristics.

Next deal with your assignment

What is the assignment really? To compare any 2 system development approach, I have chosen two topics that are System Development Life Cycle and Object-oriented Approach.

What is my research as well?

I have doing a lot of research and I have found some interesting thing. System Development Life Cycle (SDLC) is originally traditional life cycle, the waterfall model. The phases in SDLC is begin with system planning, requirement specification, followed by system analysis, design, and testing, implementation, then the last is maintenance. Once we going wrong in the implementation stage, it is hard for us to go to the earlier stage because we must change all the things, change our design even analysis, or change the requirement as well. We will change all the things and this will run out the budget and time. So waterfall model seem it is not a good approach to the system development. So, I think object-oriented approach, the concept is very good enough in doing the information system development. In OOA concept, everything or every stages is only object and its behavior. When we do the requirement specification even the system analysis and design, we are only deal with the object and behavior. It is such intangible thing and seem like abstraction but if we know or understanding the concept of this, we can complete the project effectively.

What is going to say is the differences between SDLC and OOA.