Chapter 6. Time to Market Versus Common Sense
As technology matures, it becomes cheaper. The ubiquity of the ARM processor, used in pretty much every smartphone, has dramatically dropped the price of computing. This rapid drop in the price of computing platforms at the low end has made prototyping much easier and has enabled a generation of new prototypes to be built.
Right now the proliferation of the “kitchen sink” developer boards (discussed on page 15) means it is easier than ever to prototype a product—however prototypes are not products. They’re relatively expensive, often have large form factors, and can’t be integrated into products. They’re intended to aid development, not the core of your product, no matter what some manufacturers claim.
Note
There are some exceptions, such as companies that offer wireless modules that you can integrate into your own products. These include the Particle P0 and P1, which provide the core functionality that drives their larger development boards (in Particle’s case, their Photon board). These modules offer a way to take your prototype and create a custom PCB and reuse the code from your prototype without changes.1
The “use everywhere” boards (discussed on page 15) are cheap, low powered, and can indeed be used, if not everywhere, then many places. Even if you don’t use the boards directly in your product, you can easily adapt them to your design. For example, the design of an ESP8266 breakout board that might run you $2 can be easily integrated into your own device design. At that point, you’re just paying for the ESP8266 modules, which are much cheaper than the breakout boards.
It’s at this stage, when it’s time to go to market, that you can fall into the temptation of using your prototype as your product blueprint. But that will have consequences.
Off-the-Shelf Components
If you’re manufacturing in low volume, you may well want to choose to base your connected device around an off-the-shelf board. While typically more expensive per unit than building your own custom PCB, it’s possible you can cut a large amount of up-front development time (and cost) by following this route. Taking an existing board and customizing it, or using a board designed to scale directly into production, such as the Particle Photon, means that your development time is spent adding the features that make your connected device unique and valuable rather than reimplementing an underlying platform. In this case, your final product may look a lot like your prototype.
What About the Prototype?
If your prototype is based around one of the existing single-board computers (such as the Raspberry Pi) or a network-enabled microcontroller (such as the ESP8266 or the Particle Photon), it’s tempting to continue with that into the production stage. As you move from your initial prototypes, it’s important to take a step back and consider what it is you’re trying to build. This is especially true if your prototypes were built around a “kitchen sink” board that will inevitably be large and expensive. While some of these boards can be customized—and ordered from their manufacturers in custom (stripped) configurations, by removing parts to lower the bill-of-materials costs—most cannot.
Managing Risk
There are two main types of risk when manufacturing a new product: technical and product risk. All hardware products share some element of technical risk—engineering constraints (or the laws of physics) might prevent you from being able to deliver the product. Most startups are aware of this and manage the risk fairly well. But fewer manage product risk. This is the risk that the product, once delivered, will fail to live up to expectations. It will work, but it may be unreliable; the look and feel of the product may be poor; or in some other manner the user experience may be below expectations.
The amount of product risk that your device is subject to is normally heavily dependent on how critical the device operation is to the end customer. For instance, an automated irrigation system that only polls the weather hourly may be less critical than a door lock that only works correctly once per hour. If the plants have to wait an hour for water, it’s not an inconvenience. But if employees can’t get into the building, you’ll hear about it right away!
Failing Gracefully
Leslie Lamport, an early pioneer in distributed systems, said that “A distributed system is one in which the failure of a computer you didn’t even know existed can render your own computer unusable.” By their very nature connected devices are distributed systems. There is the smart thing itself, the computer (or smartphone) that the user typically uses to interact with the device, and in many cases a cloud system behind both of these.
To manage product risk successfully, especially in high-risk systems where a small number of failures (say, one or two) over the lifetime of the system can have a severe impact on safety or revenue, it’s important to fail gracefully. A user should not be locked out of the warehouse if there’s a power outage.
Unlike systems that live purely in the digital world, connected devices live in the physical world, which means they are inherently unreliable. That unreliability must be a factor in the design of any connected system.
1 Particle offer a series of purchase options depending on the scale you intend to use their product; see “Particle Wholesale for Businesses”.