Research existing data on the topics of interest. The types of data available will vary greatly by type of business. For example, consider quality improvement records, types and rates of errors, trends in returned merchandise, and differential results across different plants, regions and teams. Look at customer correspondence and complaints. Focus groups can help to confirm or refute the validity of isolated comments and uncover additional details.
Make a list of tentative questions and get feedback. Based on all of the preceding information, try to come up with at least a dozen questions. Then go back to the same key people, as well as any others you wish to include, and have them critique your list. Ask them which questions they think you should keep and how to improve them. This process should help you narrow your list to five or six, which is about the right number for a focus group session.
Fine-tune the semantics of your questions. Pick apart every word. Think about how people react to nuances. Make sure you are asking the exact questions that you want answers to.
List potential drill-down questions for each main question. The process of conducting a focus group involves asking a question, listening to all the answers, and then asking additional questions to expand your inquiry in new directions that you might not have thought about before.
Following these procedures should net you a list of questions that will yield valuable information from your focus groups.