Systems and methods are disclosed that determine a duration and resources for testing software. In some implementations, the system performs operations including determining functions performed by applications of the software product, and determining categories based on the functions, the categories including a lowest-criticality category and a highest-criticality category. The operations also include determining degrees of change to the applications and test scripts corresponding to the degrees of change. The operations also include generating a data structure based on the categories and the degrees of change, the data structure including columns identifying the categories in an order from lowest to highest criticality. The operations also include determining weights corresponding to distances of the categories from the highest-criticality category. The operations also include determining a set of test scripts based on the weights, the test scripts, and the degree of change indicators, and determining the resources based on the set of test scripts.