The document discusses various techniques for software testing including unit testing, integration testing, system testing, and regression testing. It describes challenges in software testing like determining correctness of outputs and selecting test cases. Different strategies for test case selection are covered such as code-based, specification-based, operational distribution-based, domain-based, random testing, and risk-based testing.

1. Software Testing Basics Elaine Weyuker AT&T Labs – Research Florham Park, NJ November 11, 2002

16. Test Selection Strategies Every systematic test selection strategy can be viewed as a way of dividing the input domain into subdomains , and selecting one or more test case from each. The division can be based on such things as code characteristics (white box), specification details (black box), domain structure, risk analysis, etc. Subdomains are not necessarily disjoint, even though the testing literature frequently refers to them as partitions.

31. Risk Priority Table 9 High = 3 High = 3 Withdraw cash 4 Medium = 2 Medium = 2 Transfer money 1 Low = 1 Low = 1 Read balance 3 High = 3 Low = 1 Make payment 3 Low = 1 High = 3 Buy train ticket 6 High = 3 Medium = 2 Security Priority (L x C) Failure Consequence Occurrence Likelihood Features & Attributes

32. Ordered Risk Priority Table 1 Low = 1 Low = 1 Read balance 6 High = 3 Medium = 2 Security 9 High = 3 High = 3 Withdraw cash 4 Medium = 2 Medium = 2 Transfer money 3 High = 3 Low = 1 Make payment 3 Low 1 High = 3 Buy train ticket Priority (L x C) Failure Consequence Occurrence Likelihood Features & Attributes

47. Estimated Cost of Inadequate Testing *NIST Report: The Economic Impact of Inadequate Infrastructure for Software Testing, 2002. $22 billion $59 billion Total U.S. Economy $1,510,000,000 $3,340,000,000 Financial Services $589,000,000 $1,800,000,000 Transportation Manufacture Potential Cost Reduction from Feasible Improvements Cost of Inadequate Software Testing