The testing process Determining the test methodology phase Planning the tests

Rating Units, Integrations, and Applications

• We need to rate these issues to determine their priority in the testing plan.
• Rate based on two factors:
• 1. Damage severity level – severity of results if module / application fails.
• How much damage is done??
• Will it destroy our business? Our reputation??
• 2. Software risk level – what is the probability of failure.
• Factors affecting risk – next slide:

• Module/Application Issues
• 1. Magnitude (size)
• 2. Complexity and difficulty
• 3. Percentage of original software (vs. percentage of reused software)
• Programmer Issues
• 4. Professional qualifications
• 5. Experience with the module's specific subject matter.
• 6. Availability of professional support (backup of knowledgeable and experience).
• 7. Acquaintance with the programmer and the ability to evaluate his/her capabilities.

• Issues Affecting
• Software Risk Level

Computations

• Essential to calculate risk levels
• We must budget our testing due to high cost
• But we must temper our testing with cost/risk!
• Helps to determine what to test and to what extent.
• Use a ‘combined’ rating bringing together damage severity (how serious would the damage be?) and risk severity / probability.
• Sample calculations: A is damage; B is risk.
• C = A + B
• C = k*A + m * B
• C = A * B // most familiar with this one…

If we are including unit, integration, and applications in a test plan, we need to know how much/many resources are needed.

• If we are including unit, integration, and applications in a test plan, we need to know how much/many resources are needed.
• Thus, we need to prioritize.
• Higher the rating, and priority more allocation of testing resources are needed.
• Consider:
• Some tests are based on high percentages of reused code.
• Some applications are developed by new employees
• We typically use a 5 point scale, where 5 is high.
• (Variations include a 1-5 severity level and a probability of 0.0 to 1.0 of their occurrence.)
• Can see results for Super Teacher application in next slide.

• Combined rating method

Application	Damage Severity Factor A	Damage Severity Factor B	A +B	7xA+2xB	A x B
1. Input of test results	3	2	5 (4)	25 (5)	6 (4)
2. Interface for input and output of pupils’ data to and from other teachers	4	4	8 (1)	36 (1)	16 (1)
3. Preparation of lists of low achievers	2	2	4 (5-6)	18 (7)	4 (5-6)
4. Printing letters to parents of low achievers	1	2	3 (7-8)	11 (8)	2 (8)
5. Preparation of reports for the school principal	3	3	6 (3)	27 (3)	9 (3)
6. Display of a pupil’s achievements profile	4	3	7 (2)	34 (2)	12 (2)
7. Printing of pupil’s term report card	3	1	3 (7-8)	23 (6)	3 (7)
8. Printing of pupil’s year-end report card	4	1	4 (5-6)	26 (4)	4 (5-6)

• Super Teacher – Alternative
• Combined Rating Methods

• (Damage / p())