Digital and Agile: the foundations

In this next video, we’ll look an adapted version of The Stacey Matrix. This tool will help you to decide whether to use a Waterfall or Agile approach. 

The Stacey Matrix helps teams understand the complexity and uncertainty of a problem. It categorises these based on: 

• how clear the requirements are 
• how certain the solution is 

The Stacey Matrix has four areas: 

• The "simple" are is where we have both certainty and clarity. The solution is well understood, and the requirements are clear. This could be because it's something that's you've done before. We can use lessons learnt to help plan. Construction projects are a good example. Take building a house. It's simple to create a specification and plan a schedule to build it. 
• In the "complicated" area, there is either a lack of certainty or clarity. In some cases, there may be specific requirements, but disagreement over the best solution. For others, there may already be a solution, but it's not clear what it's supposed to achieve. These need expert knowledge and thorough analysis to find the best way forward. 
• The "complex" area is where we have low certainty and a lack of clarity. Solving these problems requires creativity and innovation. These are learning problems; we haven't solved these before. Teams need to work through experimentation and feedback to develop a solution. 
• Finally, "chaos". Here there is an uncertain solution and a lack of clear requirements. These are chaotic and unpredictable. These are often the things we avoid, but there are some situations that are unavoidable. Teams tend to need more information before they can proceed. Or, they’ll need to work in rapid iterations, to explore the problem. 

It’s important to note, simple doesn’t mean easy and complicated or complex, doesn’t mean difficult. The matrix considers how clear the requirements are and how certain the solution is. Going back to our construction example: whilst building a house is "simple", it's not easy. Unless you have the knowledge and skills to be able to, of course. 

Let's look at some examples to see how we'd use the matrix in practice. 

Our first example is a local council, resurfacing a road. This kind of thing has happened many times before. The requirements are clear and the solution is certain. The process is well documented and repeatable. This would fit into the "simple" area. 

Another example is a new community engagement platform for local residents. We could take a product that already exists and roll it out. In which case it would fit into the "simple" area. With this comes a risk. We could deliver something that isn't fit for purpose because it doesn't do what users need.  

So, instead of starting with a solution, we're first looking to understand the problem. To do that, we to find out what users need. These may be unclear and uncertain to start and could change over time. But these will inform the solution and the requirements that the team develops. Because of this, it would fit into either the "complicated" or "complex" area. 

This is where the challenge is. Most of the time, there isn't a right or wrong answer for these things. That's why it's important to gather different viewpoints. Doing so avoids delivering a simple solution to a complex problem, or vice versa. 

So, now we have categorised them, how do we choose an approach? 

First you need to recall our rule of thumb from the last video. Waterfall is linear and sequential. It does not encourage changing the process once it has started. This is ideal for situations where: 

• there is certainty 
• requirements are well-defined and agreed 
• there is stability and minimal change 

So Waterfall works best in "simple" situations. 

Agile, is iterative, flexible, and embraces changes throughout the process. It’s ideal for situations where: 

• there is uncertainty 
• requirements may evolve 
• there is instability and things are likely to change 

So in any other scenarios, that's "complicated", "complex" or "chaos", Agile works best.