Productivity (measured by lines of code per person-month) can vary by as much as a factor of 25 from the most to the least prolific coder. Quality (measured by bugs found per thousand lines of code) can vary by as much as a factor of 10 from the best to the worst software engineers.
I'm sure you can see my bias in the words above that I think quality is more important than productivity. Unfortunately, I don't have data to see the intersection of those two measures. I suspect that there is a correlation between productivity and quality. But with a diminishing return where the act of writing more code prevents a person from thinking about the stakeholder's true intention or the ramifications of the new code.
As a manager, you have to encourage an optimal mix of productivity and quality. This isn't done just by focusing on a single software engineer. This is a whole team project. For example:
- If quality is down then consider requiring stricter code reviews.
- If productivity is down then consider lighter code reviews.
- If both are down, is your team overworked?
- If both are down, is your team in need of training?
- And, yes, sometimes you do have to single one person out and say, "Slow down. You are making too many mistakes." Or, "Speed up. You are spending too much time testing your code."
- I've heard both of those admonitions. They helped make me a better developer. They helped me find balance between getting stuff done and perfectionism.
- etc...
There is no right way to optimize a development team's productivity and quality. But there is a wrong way - deciding everything for yourself. No one has all the answers and even if they did it would upset the team members to have no input.
Talk to your team! Show them the data that has you concerned and ask for input. Share details about the budget to explain why sending a few people to the QCon conference in Tokyo isn't feasible but the whole team could go to KCDC. Find ways to combine team building with training.
Reference:
Sackman, H., et al., "Exploratory Experimental Studies Comparing Online and Offline Programming Performance," Communications of the ACM, January 1968.
