A Prototype is Worth a Thousand Lines of Code

This content is syndicated from Tyner Blain by Scott Sehlhorst. To view the original post in full, click here.

A picture is worth a thousand words.  A prototype is worth a thousand lines of code.  Two key elements of product management – and of agile development are elicitation and feedback.  Low fidelity artifacts can significantly improve both.  Polished, codified prototypes can create problems that prevent you from getting the benefits of communication.

Prototyping Anti-Pattern

David Bernstein has three good quick-read articles about prototyping in the agile zone.  The first one depicts the primary anti-pattern of prototyping – mis-set expectations.


As I was walking him through the different screens I could see he was starting to get uneasy. As I talked I could see him becoming paler and tenser, as if he saw a ghost. After a while I asked him if he was ok. He finally said, “You mean to tell me that I just wrote you a check for over $100,000 for less than a week of work?”

Prototyping Caveat

The second article is quick reminder of one of the goals of a prototype.

The purpose of a prototype is to elicit feedback from others or verify a design approach will work. When doing this we generally only concern ourselves with the “happy path” through our code.

A Prototype is Not a Product

David’s third article explores a little more about the mis-setting of expectations, and provides a good parallel from the film industry.

Prototypes are rough sketches without the robustness of a final product and it is often confusing to users when we show them a half-baked version of their project for feedback, even though they know it is not yet finished.

Agile Prototyping on a Napkin

David’s advice is (good and) primarily about using low-fidelity prototypes to avoid disrupting the elicitation and feedback process.  Folks in the user experience community have known this for a long time, and adapted their processes accordingly.  Back in 2006, I wrote about prototype fidelity as part of exploring ways to use this insight in requirements gathering.  Prototyping, in particular, is a great way to elicit implicit requirements – those unspoken (“you should have asked!”) requirements that your customer or stakeholder assumed you knew, or didn’t think to tell you.

Multiple Levels of Interaction

David focused on the initial “will this approach work?” elements of getting feedback on a design – and by inference, some low-fidelity user acceptance testing that the proposed approach will meet your customer’s requirements.  Jan Miksovsky wrote an excellent article (also in 2006) that provides excellent guidance on how much fidelity to build into your prototype, depending on where you are in the design process.  This is important – the type of feedback you need at different stages of your design process varies.  Jan proposes that the first prototypes be rough sketches, just as David points out.  Jan goes on to show how and when to add additional fidelity to your prototypes (read Jan’s article to see his great visual examples).  Like I said, the user experience community has known about this for a long time.

Prototypes Are For Two-Way Communication

The key element, and the reason for creating prototypes, is to get two-way communication.  A prototype is not just a status update about your design.

A prototype is the start of a conversation.

photo of people collaborating [thanks uninen for the image]

Prototyping is not only useful for design conversations, it is critical to understanding your requirements.  Yes, a prototype will you get feedback about the design-execution of your proposed solution.  More importantly, a prototype can help you make sure you’re solving the right market problems.

Prototypes Are More Than Interface Mock-Ups

The first thing we think about, and everything you’ve read so far in this article, is about getting feedback on the user interface of the product.  Prototypes are also useful for gathering business rules*, understanding system complexity, and defining, clarifying, and validating requirements.

*In that article, I show prototypes as “not being useful” for gathering business rules.  At that time, I was thinking in terms of interface mock-ups only, not other prototypes.

Use interface mock-ups when you need feedback about user interaction.  Use other artifacts when you need feedback about other aspects of your product.  You can use prototypes as an active-listening technique when gathering market data too.  There are lots of ways to draw stuff to help with communication.

I’ve regularly used flow charts to prototype processes.  Within those flow-charts, which are initially prototypes of how the product will behave, are decision diamonds.  Those decision diamonds prototype the enforcement of business rules within the to-be-created product.  In the spirit of DRY (don’t repeat yourself), a quick polishing of your process diagram can serve as a persistent artifact of the requirements.  Just like a user interface mock-up.

In more complicated scenarios, I’ve also used UML statecharts and data flow diagrams to prototype behavior.

In the section on up-front planning in last week’s article on risk management and release cadence, I talked about the mental leap that people need to make to envision a product that doesn’t yet exist.  Prototypes are like big springboards that help people leap that chasm of imagination.

Important Safety Tip

Don’t use the wrong prototype (mock-up, flow chart, etc) for the wrong conversation or with the wrong stakeholder.  Showing when and where business rules are being enforced (in the process being designed) is great for getting feedback about your interpretation and potential embodiment of those rules.  It will be a disaster if you try and have this conversation with someone who is not the owner of those policies – like a representative user.  Sometimes, policies are “owned” by non-technical people who struggle to read diagrams.  You may have to walk them through how the diagram works.  They’re smart – they’ll get it.

Just remember – use the right prototype to emphasize the right ideas, and elicit the right feedback.


Post to Twitter Post to Facebook

Leave a Reply

Your email address will not be published. Required fields are marked *

5 + 2 =

There are 101 ways to do anything.
To find the best way, sometimes you need expert help

What People Say

“Kelly was engaged as a Program Director on a complex business and technology transformation program for Suncorp Commercial Insurance. Kelly drew on his key capabilities and depth of experience to bring together disparate parties in a harmonised way, ensuring the initiate and concept phases of the program were understood and well formulated. Excellent outcome in a very short time frame. ”


“Kelly and I worked together on a very large project trying to secure a new Insurer client. Kelly had fantastic commercial awareness as well as his technical expertise. Without him I would never had secured this client so I owe a lot to him. He is also a really great guy!”


“I worked with Kelly whilst at Thoughtworks and found him to be a most inspiring individual, his common-sense approach coupled with a deep understanding of Agile and business makes him an invaluable asset to any organisation. I can't recommend Kelly enough.”


“Kelly is an Agile heavy-weight. He came in to assess my multi-million $ Agile development program which wasn’t delivering the right throughput. He interviewed most of the team and made some key recommendations that, when implemented, showed immediate results. I couldn’t ask for more than that except he’s a really nice guy as well.”


“Kelly revolutionised the way our digital department operated. A true advocate of agile principles, he quickly improved internal communication within our teams and our internal clients by aligning our business and creating a much enhanced sense of transparency in the decisions the business was making. Kelly also introduced a higher sense of empowerment to the development teams...”


“Kelly’s a leading program director with the ability to take charge from day one and keep strong momentum at both a program and project level driving prioritisation, resourcing and budgeting agendas. Kelly operates with an easy-going style and possesses a strong facilitation skill set. From my 5 months experience working with Kelly, I would recommend Kelly to program manage large scale, complex, cross company change programs both from a business and IT perspective.”


“I worked with Kelly on many projects at IPC and I was always impressed with his approach to all of them, always ensuring the most commercially viable route was taken. He is great at managing relationships and it was always a pleasure working with him.”


“Kelly was a great colleague to work with - highly competent, trustworthy and generally a nice bloke.”


“Kelly was a brilliant CTO and a great support to me in the time we worked together. I owe Kelly a great deal in terms of direction and how to get things done under sometimes difficult circumstances. Thanks Kelly.”


“Kelly came to the department and has really made a huge impact on how the department communicates, collaborates and generally gets things done. We were already developing in an agile way, but Kelly has brought us even more into alignment with agile and scrum best practices, being eager to share information and willing to work with us to change our processes rather than dictate how things must be done. He is highly knowledgable about agile development (as his active blog proves) but his blog won't show what a friendly and knowledgeable guy he is. I highly recommend Kelly to anyone looking for a CTO or a seminar on agile/scrum practices - you won't be disappointed!”


“Kelly is an extremely talented and visionary leader. As such he manages to inspire all around him to achieve their best. He is passionate about agile and has a wealth of experience to bring to bear in this area. If you're 'lucky' he might even tell you all about his agile blog. Above all this, Kelly is great fun to work with. He is always relaxed and never gets stressed - and trust me, he had plenty of opportunity here! If you get the chance to work with Kelly, don't pass it up.”



To explore how we can help you, please get in touch