Product Marty Cagan

Product Validation

The past few newsletters have had references to what I call “Product Validation.” This refers to verifying that the product spec (PRD) is describing a product that you know will be successful, but doing so without actually building out and deploying the product.

This used to be a very expensive and difficult thing to do, and was generally only done for products that were very expensive to actually tool and manufacture, such as automobiles.

However, for just about every type of product today, the costs to produce effective prototypes or simulations has come down so far that I am amazed that I continue to encounter product teams that don’t do this.

One of the biggest and most common mistakes product teams make is to have far more confidence in their product specifications than they should, and they move forward and think they’ll adjust the product – if necessary – once they get beta feedback. But of course beta is far past the time for major changes, and it is little wonder so many initial product releases are so far from the mark.

As product manager, it is your responsibility to ensure that this doesn’t happen to your product. The key to doing this is to prove to yourself and to the rest of the product team that the spec you give them describes a winning product. You can do this, and it costs far less than you probably think.

There are actually three important types of validation that you need to perform before you hand over a final product specification to the product team:

Feasibility Testing

One immediate question is whether or not the product is going to be buildable, with the technology available. Your engineers and architects should be very involved in investigating technologies and exploring possible approaches. Some paths will be dead-ends, but hopefully others will prove viable.

What is most important is that if there are obstacles the engineering team considers insurmountable in this product’s timeframe, it is important to know this now rather than discovering this much later in the process after the time and money has been lost.

Some products have more technical risks than others, but if yours has significant risks regarding feasibility, make sure you address them early.

Usability Testing

Your product designers (UI/interaction designers) will be working very closely with you to come up with ways of presenting the functionality in the product so that the different types of users can figure out how to actually use the product.

Usability testing will often uncover missing product requirements, and also, if done well, identify product requirements that are not as necessary as originally thought. You should plan on multiple iterations before you come up with a successful user experience.

The purpose of the usability prototype is to have something to test on real people, and usability testing is the art and science of getting useful feedback on your product from your target customers. Certainly the product manager and designer will use the prototype and learn a great deal from it, but there is no substitute for putting the prototype in front of actual people from the target customer base.

Note that for usability testing purposes, it is perfectly fine if complicated back-end processing is simulated – the key is to evaluate the user experience.

Desirability Testing

Finally, it is not enough to know that your product is feasible to build and will be usable, but what really matters is whether or not your product is something users will want to buy – i.e. how much do users and customers like and value what you’re doing?

This testing can typically be combined with the usability testing, and the prototypes used can generally be the same, but in usability testing you’re seeing if users can figure out how to do the necessary tasks, while in desirability testing you’re seeing if they actually care about those tasks and how well you solve them.

For a few small product efforts, simply working your ideas out on paper may be sufficient. But for most products, with complex user interactions or new uses of technology, these prototypes are absolutely critical in order to assess whether or not the product will meet its objectives.

The prototype may be a physical device, or it may be a quickly assembled version of a software product. The key is that it needs to be realistic enough that you can test the prototype on actual target customers and they can give you useful feedback.

Until recently there was debate over the relative merits of “high-fidelity” prototypes (what I’m describing), versus “low-fidelity” prototypes (essentially paper drawings). Today I consider this debate meaningless, because the cost of high-fidelity prototypes has dropped so low, and the quality of the feedback is so much higher.

In the past, there were two major obstacles to these types of prototyping. The lack of good prototyping tools meant that it could take a long time to actually construct the prototype. Another problem was in unenlightened management not understanding the difference between a prototype and the real product, and the teams would get pressured to use the prototype as the basis for the final product, with predictable results in the quality of the implementation.

Today, there are outstanding prototyping tools that can let engineers or designers rapidly create very functional prototypes (often in hours or days) that can effectively emulate the future product, to the degree necessary, and form the basis of realistic user testing. Moreover, most managers today understand that building a simulation and building the actual product are very different – akin to building a scale model of a house, and building the actual home.

These are not the only ways to validate your product – especially for internet services there are other techniques that are also easy and effective – but I can’t emphasize enough how important and valuable it is to validate your ideas before you go and actually build the product. There are always surprises, and it is far better to discover them early rather than to wait until the product is in beta or released. Further, once the real engineering begins, a special type of inertia sets in, and it becomes very difficult to make significant changes and the costs of the changes rises dramatically.