Object Oriented Analysis And Design- IT0207 III Semester UNIT-IV

1.Apply design axioms to design classes 1.1 Refine and complete the static UML class diagram 1.2 Iterate and refine again 2. Design the access layer 2.1 create mirror classes 2.2 Identify access layer class relationships 2.3 simplify classes and their relationships 2.4 Iterate and refine again 3. Design the view layer classes 4. Iterate and refine the whole design

Corollary 1 Uncoupled design with less information content Corollary 2 Single process Corollary 3 Large number of simple classes Corollary 4 Strong mapping Corollary 5 Standardization Corollary 1 Design with inheritance

Axiom 1.The independence axiom Maintain the independence of components Axiom 2. The information axiom Minimize the information content of the design

Designing classes: The process 1. Apply design axioms to design classes, their attributes,methods,associations, structures and protocols. 1.1 Refine and complete the static UML class diagram 1.2 Iterate and refine

Attributes types 1. Single –value attributes 2. Multiplicity or multivalue attributes 3. References to another object Attributes presentation : + public visibility # protected visibility - private visibility

Several methods constructor destructor conversion method copy method attribute set attribute get I/O methods

Rules that satisfy OO system *System must support complex objects *object identity must be supported *object must be encapsulated * System must support types or classes * System must support inheritance * must avoid premature binding * System must be computationally complete * System must be extensible

Second rule *Must be persistent * Must be able to manage very large databases *Must accept concurrent users * Must be able to recover from hardware and software *Data query must be simple

Access layer performs two major tasks * Translate the request * Translate the result

1. Mirror the business class 2. Define relationships 3. Simplify classes and relationships 4. Iterate and refine

1. Macro level UI design process 2. Micro level UI design activities 2.1 Designing the view layer objects by applying design axioms and corollaries 2.2 Prototyping the view layer interface 3. Testing the usability and user satisfaction 4. Refining and iterating the design

1. Define relationships among the view (interface) objects 2. Iterate and refine

Apply micro-level UI design rules and corollaries to develop the UI Iterate and refine

How would you differentiate good design from bad design? what is the basic activity in designing an application? Why is a large number of simple classes better than a small number of complex classes? How can encapsulation, modularization and polymorphism Why are people not utilizing reusability? How would you decide a subdividing your classes into a hierarchy of super and subclasses. What are the challenges in designing with inheritance? How do you distinguish transient data from Persistent data? What is a DBMS? What is a relational database? explain tuple, primary key and foreign key. Is a persistent object the same as a DBMS? What are the differences? What is a database schema? What is the difference between a schema and meta -data? What is DDL? What is a distributed database? What is concurrency control? What is shareability? What is a concurrency policy?

Object oriented system development by Ali Brahami Object oriented methodology by Booch A text book on UML by Srimathi