Visually, evaluation is the “final phase” of the process. However, it’s impossible to successfully complete a cocreation process if you simply introduce the concept in the market after the final phase and see whether or not it “catches on”.
Continuous testing, assessing and adjusting should be a reflex during the entire cocreation process. When defining the challenge, you automatically set a number of benchmarks. In the case of the smart rubbish bin for instance, the design had to meet nine criteria.
These criteria are used in every phase of the cocreation process: to go from one hundred ideas to three ideas, to narrow down those three ideas to one idea, to give the first design for that idea a go/no-go, to adjust the prototype etc.
And you continue using these criteria until you reach a result that meets them for the most part: your MVP (Minimum Viable Product). You can then market the MVP, making sure to take into account the end user’s feedback and to make the necessary adjustments.
It’s only by proceeding in this manner that you can avoid unnecessary investments and obtain a well-developed product that actually has a chance of being successful.
However, you should make sure that you have the right people and partners to test and evaluate. For instance, passers-by are not the right people to test whether the measurement technology in the new smart rubbish bin is up to standard. It’s the responsibility of the local authorities to find out whether the sensors are functioning properly, whether it’s easy to capture the data and whether these data are relevant. What you can ask passers-by is whether they think the rubbish bin is easy to use and easy to find, what their opinion is about the "look & feel” etc.