Performance testing is a type of non-functional testing activity that is carried out to determine an application’s response time, behavior and overall performance. LoadRunner is one of the most widely used performance-testing tools since it uses minimal hardware resources and is extremely efficient. Flexible and versatile scripting engine to extend tests with success-failure checks, thus making testing more intelligent. Ramping of many concurrent users to make the most representative testing possible. Integration of external measurements in test scenario's. Extensive vendor documentation and help system included. Extensive experience and support on various fora, blogs and many other support resources. Good availability of expertise in the form of programmers and hardcore testers.
1) Cost is the major factor that should be considered by HP because it prevents many users from using this product. Despite many advantages of Loadrunner, other open source alternate solutions like Neoload are mostly used.
2) It takes lots time in scripting, if the test cases are very complex, it can take even days to make one script. Re-usability of these complex scripts also becomes a complex job, mostly when the application build are changing frequently. The tool always demands a script modification or re-scripting, in case of changes in application build.
3) Complexity. LoadRunner is not simple to learn by installing it and "doing it". Especially when using different data sources to do cross measurements of system performance. Performance testing with a tool like this requires planning and skilled resources. Fortunately these are easily acquired these days.
LoadRunner, when used judiciously can give you an accurate picture of end-to-end system/application performance. When used in the development cycle, all the performance bottlenecks can be easily identified and eliminated.