The Unified Approach The UA approach establishes a

The Unified Approach The UA approach establishes a unifying and unitary framework around their works by utilizing the UML to describe, model & document the s/w development process. It revolves around the following processes & concepts. The processes are: Ø Use-case driven development Ø OO analysis Ø OO design Ø Incremental development & prototyping Ø Continuous testing. The methods & technology employed include: Ø UML used for modeling. Ø Layered approach. Ø Repository for OO s/m dvlpmt. Patterns & frameworks. Ø CBD.

The Unified Approach OO Analysis consists of the following steps: 1. Identify the actors. 2. Develop a simple business process model using UML activity diagram. 3. Develop the use case. 4. Develop interaction diagrams. 5. Identify classes.

The Unified Approach OO design process consists of : 1. Designing classes, their attributes, methods, associations, structures & protocols, apply design axioms. 2. Design the access layer. 3. Design & prototype user interface. 4. User satisfaction & usability tests based on the use cases. 5. Iterate & refine the design.

The Layered Approach Ø In a 2 -layered s/m, user interface screens are tied to the data through routines that sit directly behind the screens. Ex: a routine that executes when we click on a button. Ø With every interface we create, we must recreate the business logic needed to run the screen. Ø A better approach to s/ms architecture is one that isolates the interface from the functions of the business. Ø This approach also isolates the business from the details of the data access.

The Three-Layered Approach Consists of : 1. A view or user interface layer, 2. A business layer & 3. An access layer. The Business Layer: contains all the objects that represent the business. The responsibilities of the business layer are : Model the objects of the business & how they interact to accomplish the business processes. Business objects should not be responsible for the following: Ø Displaying details. Ø Data access details. The business objects are identified during the OOA. Use cases can provide a wonderful tool to capture business objects.

The Three-Layered Approach The user interface (view) layer: consists of objects with which the user interacts as well as the objects needed to manage or control the interface. This layer is responsible for two major aspects : Ø Responding to user interaction: the user interface objects must be designed to translate actions by the user into an appropriate response. Ø Displaying business objects: this layer must paint the best possible picture of the business objects for the user.

The Three-Layered Approach The Access layer: Contains objects that know how to communicate with the place where the data actually reside. It has the two major responsibilities: Ø Translate request: it must be able to translate any datarelated request from the business layer into the appropriate protocol far data access. Ø Translate results: it also must be able to translate the data retrieved back into the appropriate business objects & pass those objects back up into the business layer. Access objects are identified during OO design.