It helps you understand who you are, what might happen to you, and where you need to go. It makes it easier to set priorities. In a small organization, one person each from the major functions might make a good thinking group. SWOT analysis is not planning. You are trying to understand the way things are, not how they should be.
Planning comes later.
Make sure you record your thoughts as you go. A tape recorder might be a good idea. Consensus is not necessary. Don't try to force agreement. Record disagreements for consideration later.