Coupling Interaction: It occurs due to methods of a class invoking methods of other classes. Component Coupling: refers to interaction between two classes where a class has variables of the other class. Obj Inheritance coupling: if one class is directly or indirectly sub class of other.

Cohesion Method: It focuses on why the different code elements of a method are together within the method. same as functional cohesion, X and Y are a part of single functional task. Related to performing single function. Class: Focuses on why different attributes and methods are together in this class. Inheritance: why classes are together in hierarchy.

Software Metrics It is a unit of measurement of software product. The continuous application of measurement based techniques to the software development process and its products to supply meaningful and timely management information , together with the use of those techniques to improve that process and its products.

What and Why How to measure the size of a s/w How much will it cost to develop a s/w? How many bugs can we expect? When can we stop testing? When can we release the s/w? What is the complexity of a module? What is the module strength and coupling?

User Interface Responsible for all the interaction with users Characteristics Speed of learning – should be easy to learn A- component based- similar to interface of other application B- Use of metaphors and intuitive command names- speed of learning increases if the command names are based on day 2 day real life eg.

Speed of use- it is determined by the time and user effort necessary to initiate and execute different commands. Speed of recall – Error prevention- good interface should minimize the scope of committing errors while initiating different commands. Attractiveness- A to use Feed back- provide feedback to various user actions. Support for multiple skills level- procedure for different categories of users.

Error recovery- allow user to undo a mistake User guidelines and Online help

Types of user Interfaces Command language Based- difficult to learn Require user to memorize the set of commands Menu Based- (a) scrolling menu: (b) Walking Menu: (c) Hierarchical Menu: Direct manipulation Interface

Software Configuration Management Change Management more commonly called S/w configuration mgt. It is applied throughout the s/w process. SCM activities are developed to (1 ) identify change, (2) control change, (3) Ensure that change is being properly implemented (4) report changes .

A SCM Scenario Project Manager: In charge of a s/w group A configuration Manager: In charge of SCM Procedures and policies. SE: Responsible for developing and maintaining the s/w product. Customer: Who uses the product

Elements of a configuration Management System Component elements- a set of tools coupled with file mgt (a Database) that enable access to s/w config item. Process elements- a collection of procedures and tasks that define an effective approach to change management. Construction elements- A set of tools that automate the construction of s/w by ensuring that the proper set of validated components. Human elements- s/w team

Baselines s/w configuration items- suite of test cases, or a named program component( function, java applet) Before a s/w configuration items becomes a baselines, change may be made quickly and informally. However once the baseline is established , changes can be made but a specific formal procedure must be applied.

Once base line is established, it is copied from Database into engineers private work.

S/w configuration items

The SCM Repository

The SCM Process

What is reliability at the time of release? Which test technique is more effective? Do we have strong program or weak test suite?

Token count It is classified as either operators or operands. Variable, constants- operands +,-,/,*, while ,for, printf, eof n=n1+n2 n= vocabulary of a program n1= no of unique operators n2= no of unique operands

Length of the program in terms of the total no of tokens N=N1+N2 N1- Total occurrences of operator N2- Total occurrences of operands Volume- actual size of programs (bits) V= N*log2n