A frequently asked question I encounter is: What is the ideal developer-to-tester ratio? Some people even propose a ratio of 1:3 without any supporting evidence.
If someone suggested that "you must own a two-seater Mini Cooper if you're a couple, or a four-seater sedan if you have two kids," wouldn't you find that a bit unreasonable? Each person has unique needs influenced by various factors.
For instance, what will the car be used for—personal use or commercial purposes? Will it be transporting only passengers, or will it also carry cargo? Does the driver have a preference for automatic or manual transmission? How far will the car be driven daily? Is fuel economy a significant concern for the owner?
Now, how does this connect to determining the developer-to-tester ratio? The key is: who is your target audience? While there is no universally ideal ratio of developers to testers, assessing several factors can help guide you in finding the right balance. Here are a few to consider
- What type of business are you in? Healthcare, finance, eCommerce, etc.?
- How complex is your product?
- What is your current test maturity level (TMMi)?
- What types of testing will be conducted? Is performance or security important, or just functionality?
- How many configurations need to be tested?
- How is the release cycle structured?
- What is the velocity and quality of the code when it reaches the testing phase?
- Are testers cross-trained?
- What’s the skill level of the testers
- How early are testers involved in the process?
- Is quality considered everyone’s responsibility? Do developers conduct unit tests?
- What is the budget?
On the other hand, simply increasing headcount in testing won’t necessarily improve outcomes and could even be counterproductive. For instance, if you need to travel 600 miles, does adding three random people to the car make you go faster?
It might save time because drivers can switch without long breaks. But what if the car has a manual transmission and not all drivers know how to operate it? What if one driver doesn’t have a license? What if another is still learning?