List some factors related to your customers (internal or external) that could potentially affect their needs. These factors could be demographic, such as age, sex, work experience, and place of residence. The factors might pertain to how the customer uses your product or service. Choose two to four of these factors and define two levels for each. Construct a factorial pattern using the factors and add a centerpoint. Use the pattern as a basis for selecting customers to interview to determine their present and future needs.