Some cases in which there is low or negligible benefit of going in for automation of test cases

Automation of test cases can lead to major benefits for teams that implement the automation of their test cases in an effective way, and with a proper strategy. However, this is not an absolute, and there are many situations when it may not be worth the effort to do an automation. One needs to do an analysis of the cost / benefits of going in for automation (but be sure to include long term benefits as well - such as for a regular long cycle, it may be worth going in for automation if it is beneficial in the long term). Some of the situations in which it may not be beneficial to go in for a test automation strategy are:
- Calculate the effort required for writing the test cases for automation: Just because you have test cases for manual testing does not mean that you can go in for automated testing. You would need to convert those test cases into automation script, and depending on the size of the product, this can be a sizable effort. The effort required for this (converted into number of people required) is a prime input into the calculation of whether test automation should be done.
- How likely is it that there will be a need for automation in the future. Automation has much more value if there is a constant ongoing effort for testing. If there is not likely to be much more need of testing of the product, then the benefit that you can get by automating the test cases is significantly reduced.
- Diversity of cases. This is related to the overall effort required for automation. If there are less chances of situations of load testing or testing of multiple input parameters, then some of the benefits of going in for automation of testing reduce
- When the test software is expensive. Say you have a small product or project that sells for a few hundred dollars or less, and is also not sold in appreciable numbers, then it does not make sense to go in for the more commercially available automation softwares that can be fairly expensive
- When the test case is likely to change during the cycle. If you consider the case of an automation software that is UI based, and the UI of the target application keeps on getting modified, then the cost of modifying the automation test scripts to take the changes in the UI can increase the costs involved in an automation strategy
- Getting people to use these automation testing tools is expensive. Using these automation testing tools can take some level of expertise, and it can take some amount of experience to master using such tools (even though many of them claim that they are simple to use). People who are skilled in using such tools can be expensive to hire, and retain.