For those in L & D, internal and external training, and instructional design roles, we have the goal of creating engaging and effective learning content in the optimum learning experience. Ideally that happens through tried and proven methodologies , frameworks, and models. The friends at your party include ADDIE, SAM, Gagné , and Kirkpatrick, plus a few new kids on the block and a couple has-beens. All of these have the same ultimate goal–to guide you in learning creation so that it is effective. Some of them are decades old, while others have modern spins on old ideas. Truthfully, they are all good and worth your time to explore, but in reality, I find that there is no single one that is only used, nor any one that is necessarily better than the others–because it all depends on the project itself and the people involved.
They might use different terminology, but essentially for many there is still a basic high level flow. And others might focus in on certain aspects elements of the process. For example Kilpatrick is more focused on evaluating effectiveness than how you involved users in testing throughout.
What I have found is that I bring in strategies from all of these depending on the situation. Yes, if all the parameters in your project are constant, then you might have the luxury of choosing one approach and sticking with it to the end. But I am pretty sure in the history of learning , this has never happened. In reality, project deadlines change, priorities change, project finances change, and project stakeholders change. Your boss had originally given you 8 weeks, but has changed it to 4 weeks. The budget for the course was $25K, but got cut to $10K. The SMEs change mid-stream and have different styles and beliefs and opinions. The team you partner with for user testing and client feedback has a reorganization of leadership.But there are other elements that are part of course-building experiences, such as your own style and personality, the style and personality of the SME, the culture of your company, and the availability of people related to the project.
If you look at some of the more modern methodologies, such as SAM, they still follow the same high level flow of basic design (i.e. ADDIE is Analysis, Design, Development, Implementation, Evaluation), but they incorporate threads of Agile throughout.
I would say the common thread I see regardless of which is used is adaptability and flexibility, but also just common sense. Be willing and ready to change the process. No course will ever be perfect. You could always spend just a bit more time on this or that. One trick that I found that was always helpful was just to take some time away, maybe just a day or two. This gives you fresh eyes that will look differently.