Summary of testing techniques

You can use a variety of testing techniques in your test plan. Table 6-1 summarizes the advantages and disadvantages of various testing techniques and tools:

**Table 6-1: Testing techniques’ advantages and disadvantages**
Technique	Description	Advantages	Disadvantages
Ad hoc testing	Manually walk through important application processes, screens, and reports	Easy to implement Tests front-end applications and back-end servers	For complex applications, code coverage is too small Difficult to distinguish front-end and back-end bottlenecks if response time is a determining factor Impossible to obtain production multiuser load, which misses concurrency and capacity issues altogether
Manual performance scripts and cases	Specify input and compare with known outputs	Easy to implement Common basis for regression test suites Back-end focus may help locate the cause of a problem	Only tests backend server Impossible to obtain production multiuser load, which misses concurrency and capacity issues altogether No ad hoc query testing Depends on strong analysis of process or transaction profiles
Keystroke capture	Record and replay keystrokes and mouse clicks into an application	Tests front-end applications and back-end servers Tool may include powerful language and looping capabilities to manipulate inputs for multiuser concurrency and capacity testing	Heavy processing requirements, may require additional hardware May increase development time for creating multiuser test simulations, and add time for debugging test harness Depends on strong analysis of process or transaction profiles
Concurrency and capacity testing	Use third-party load-testing tools	Tests both front and back ends Language and looping constructs make these tools	Heavy processing requirements for test tool—may even require additional hardware, or else results may be skewed Learning and development curve to write multiuser test simulations Risk of bugs in test harness may skew results Dependent on strong analysis of process/transaction profiles
Transaction generation	Thin client to simulate user execution of transactions	Strong multiuser load testing Focus on back-end server issues	May increase development time for creating multiuser test simulations, though learning and development curve generally less than keystroke capture tools Adds time for debugging test harness to prevent skewed results Depends on strong analysis of process or transaction profiles
Production load capture	Use tools to capture real transactions in a production environment, including performance and semantic characteristics, and resubmit in a test environment for analysis	Tests real production loads, including ad hoc queries Especially useful when little or no analysis of transaction profiles is available	Introduces new software into a production environment Production and test system configurations must be identical for valid performance analysis