How will this affect customer relationships and the competitive situation of our company? what is the best strategy for preventing this condition?
The best strategy is to agree on a (free) post production support period prior starting the contract with client. Our company, for example, is providing a free one week post production support after deploying the software product in the market! For future services/support including bug fixing and enhancements you can continue with hourly based cost model!
We can schedule a call for specific cases for your convenience and would be glad to give a feedback/suggestion!