Jawab:

In order to consider the fact that the program switched from operational system A to operational system B, the computer manager could include a categorical variable in her analysis to indicate which operational system the program was running under at each time point. This variable could be included as a predictor in a linear or nonlinear regression model, along with the other predictor variables already being considered (such as program size and program complexity).

Alternatively, the manager could create separate models for the data collected under each operational system, and compare the prediction power of the two models. This would allow her to determine if there is a significant difference in program efficiency between the two operational systems and which system is better for the program.

Additionally, the manager could use a time series analysis method to analyze the data, as it would allow her to take into account the order of the data points and the possible effect of the switch from one system to another on the program efficiency.

It is important to note that the method chosen will depend on the specific characteristics of the data and the research question. The manager should also ensure that the data collected is sufficient and unbiased to make valid conclusions.