After the sesion it's time to review the prototyping session for any learnings you can use. Split these into:
Must fix - anything that causes your users a blocker to using your product or service at all (i.e. a website for visually impaired users that doesn't work well with the most popular screen readers such as JAWS).
Actionable insights - these are points that have arisen that are not blocking a goal being acheived but that you could act on and provide a significant experience improvement to your future users.
Bubble points – these are things that have come up with during the session that you may want to explore deeper. As these are often not easy to pinpoint or act on insights, they can be easier to digest if you transform them into How Might We questions. Discard them if they are a distraction but prioritise them if they have given you some insider insight that may transform your understanding of how to solve your core problem for your user group.
Take the learnings you have digested and act on them. Make any must fixes and see how you can implement the actionable insights. With the bubble points, did they fundamentally change how you will approach fixing this problem for your user group? If so, build a new prototype that will allow you to test if this solution may work better.
Once you've improved your prototype, it's time to get it in front of users again and implement new learnings.
When does a prototype end, a pilot begin and a product or service go live?
In truth, this varies widely depending on the product or service you are delivering and the philosophy of your organisation. My preferred route is to not have a 'go live' date but rather flesh out scrappy prototypes into higher fidelity pilots and accidentally go live in, unwhittingly, in the process. This is not a method that well-established organisations enjoy but it is a method that moves you to action faster and that remove the fear of launch. In fact, I never stop seeing products and services as prototypes as it encourages me to maintain an improvement and innovation mindset.