Final answer:
A project manager should use historical data as a guide for developing time and cost estimates while adjusting for the current project's unique aspects. It is essential to refine estimates using modern techniques and consult with the project team for accuracy.
Step-by-step explanation:
A project manager should use historical data from previously developed information systems as one of the factors to develop time and cost estimates for new projects. However, it is important to adjust these estimates based on the specific context and requirements of the new project.
Factors such as project complexity, team experience, technology changes, and the uniqueness of project requirements can significantly affect time and cost estimates.
While historical data can provide a useful benchmark, project managers must also consider current market rates, potential risks, inflation, and the availability of resources.
They may use techniques such as analogous estimating, parametric estimating, and bottom-up estimating to refine their estimates. Collaborating with the project team, stakeholders, and subject matter experts can further enhance the accuracy of time and cost predictions.