Object Oriented Analysis:
With structured methodologies we develop the solution through two basic models: process or function models and data models separately.Object Oriented methodlogy radically change this division between data and function and combie them in object or class model. Systems are viewed in this methodologies through interacting objects each posses its data and function or method. Object has its own behavior (determined by its method) and interact with other object or the environment. As object has a known behavior it becomes possible to group them in a class of objects or simply a class. Also, object becomes instance of class or instantiated from its class. Objects created from a class will inherit all or some of its properties and behavior. With these concept objects are considered to be the building units of our system. This unit may referred to as business objects (or business class) and systems can be built from predefined business objects. These business objects can be configured to be reused in various fields or applications as far as they carry the same pattern. With this methodology we have many new concepts as Reusability and Process Pattern. Developing business objects shifts the development efforts to business analysis instead of software development which benifit a lot from the new generation of Object Oriented Programming and Development Environment.
Methodology View:
Today we all have access to computers and use it daily in various fields and environment. Also, with home computers there are many software which suite various levels of skills and experience of the users. There are also many forms of Computers ranging from large and sophisticated computers for professionals to simple desktops and family-use portable computers, to iPads and smartphone, all use applications designed to help users to fulfill their specific needs. With these computers there are millions using the internet to connect to social networks through many software applications as facebook, twitter, linkdl, as examples. All these gadgets with its software passed through number of stages in order to be realized in its present form. Each started as an idea and evolved through sequence of iterative process to finally become in the shape and form we are using now. With this view we can distinguish between two main categories of software such as Computer applications, and Information systems.
cairoAli Bahrami-1998
Advantage and Disadvantage of OOM

Focuses on data rather than the process

Functionality is restricted within objects.
This may pose a problem for systems
which are intrinsically procedural or
computational in nature

The principles of encapsulation and data
hiding help the developer to develop systems
that cannot be tampered by other parts
of the system.

It cannot identify which objects would
generate an optimal system design

The principles of encapsulation and data
hiding help the developer to develop
systems that cannot be tampered by
other parts of the system

The object-oriented models do not
easily show the communications
between objects in the system.

It allows effective management of software
complexity by modularity

All the interfaces between the objects cannot
be represented in a single diagram

cairoAli Bahrami-1998
System Analysis and Design:

System analysis and design are concerned with the investigation of an organization and the design and implementation of a computerized solution to that organization needs. To analyze a system is to identify its components (devices, people, rules and procedures) and their interrelationships in order to determine its objectives, requirements, and priorities. The analyst must find ways of representing organization as a whole system, taking into consideration any economic behavioral and technical constraints. To know more about systems analyst job from the internet click here. and visit the international institute of business analysis(IIBa).