Is an agile approach always the right answer? Are there times when the more traditional, sequential, also known as waterfall, approach makes sense? How do you decide if you really need agility
I know that there are agilists who would like to string me up for saying that there is anything that wouldn’t benefit from an agile approach, but sit back down. Listen. Nothing is for everyone.
I just drew this analysis matrix to recognize opportunities that favor one approach over another.  I am sharing it here for your input. Please share your thoughts.  Also read my post about agile is NOT a NOUN to understand that I am talking about Agility Enabling Practices and the state of being nimble, when I say the word agile here.  I fully believe that every project, every act of creation should use good 21st century leadership and management practices!  That is not an option.  You must respect people, you must push decision making down to the level of the information, leaders must have the heart of a servant. But that is not the purpose of this article.
People often struggle with deciding if this or that should be approached with agility enabling practices. but it really is quite simple.

It’s all about the RISK, ’bout the risk, ’bout the risk…

agilityorsequential
Determining the optimal approach is about looking at risk reduction. We need need to understand in what circumstances a sequential approach reduces risk and where an agile approach reduces risk.  Both approaches are attempting to do the same thing. They just have different basic assumptions.  One assumes you can know the outcome ahead of time and that change in the system will be low, and the other assumes  you can’t know until you see it, and that change is frequent and should be used to benefit the customer.
The edge cases where you have high high, and low, low are opportunities for a mixed approach.  If you have high process knowledge then you don’t need an agile approach to help you figure out how to make your thing. But if change is also high, then you do want quicker delivery in order to learn and adapt to the changes that are happening.
On the other hand if you have Low process knowledge and low change. You will want to take an agile approach because you don’t really know how to make what you are making,  your knowledge of the processes is low. Taking an agile approach will help you because you can build a little something and then add and adapt as you learn about the system you are creating.  As Woody Zuill says, “It is in the doing of the work that we discover the work that we must do.”
Isn’t that so consultant of me. Use a double axis chart. 😉 but it works.  The thing to know is that change, especially culture change, takes a long time.  I talk about it in my book. It takes dedication and commitment but it is possible.