Here are three very important things to know (and links to other key posts on this topic):
First, every small group model, system or strategy comes with a unique set of advantages and disadvantages.
I like to say, "there are no problem-free small group models, systems or strategies." That said, be prepared to acknowledge that there is an upside and a downside to every model.
If you like the semester model, don't overlook the challenge of confirming which leaders will commit for the next semester and what they will study...early enough to assemble your catalog of available groups. If you like the cell group model, don't turn a blind eye to the reality that groups don't always birth new groups fast enough to absorb the number of unconnected people in your congregation. If you like the campaign-driven strategy, be prepared for messy.
Second, the model you choose should be predetermined by what you hope to accomplish.
Before you choose a small group model, you should have already identified the business you are in, the customer you will be serving and what you will call success. I know that may seem like a strange way to say something about ministry, but it is the best way to point out a very important truth about a very important topic.
For example, if you're in the business of giving group members an in-depth Bible study experience, you will be wise to choose certain models. If the customer you want to serve will be unchurched neighbors, friends, co-workers and family members...it will predetermine certain models and not others. And if you dream of more people in groups than you average at your weekend services, you must choose the right model, system or strategy.
See also, If I Was Starting Today (I've written at length about this important idea in this series of posts).
Third, you should choose your model carefully and only change it after careful consideration.
A lot rides on decisions you make. Changing models every time you read a new book or attend a conference will shake the confidence of your group leaders and coaches. Changing models frequently can be quite toxic.
Aren't there reasons to change models or implement a new strategy? Absolutely. A careful analysis of your small group ministry and its results may drive you to rethink the model you've chosen. After all, "your ministry is perfectly designed to produce the results you are currently experiencing." If you want different results, you'll need a different design. See also, 5 Signs Your Small Group Ministry Design Is Inadequate and 5 Toxic Small Group Ministry Moves.
Finally, there is a lot to know about small group models, systems and strategies!
They are not all the same and they don't all accomplish the same thing. They each have unique advantages and disadvantages. Some make it easy to find leaders. Some make it easier to connect beyond the usual suspects. Some more reliably make disciples. You can learn much more in the additional posts below.
My mini-course, How to Choose the Best Small Group Model (for your church) provides the detailed coaching and counsel that many churches need.
Image by Loughborough University Library