ALERT: I’m not pulling any punches with this one. If you are looking for a balanced argument including thoughts on some potentially good reasons to measure LoC, you won’t find it here. The best reasoning I can give for the existence this article: it gives me something to point people to when they ask for my opinion on the topic.
Counting Added Lines of Code as a Measure of Productivity
“Any process or procedure that incentivises based on creation or destruction of lines of code is missing the point entirely.”
Software Craftsman – Pluralsight
Counting LoC drives bad behavior and is easily manipulated. It leads to developers being less concise and writing code that is difficult to maintain. There are so many ways to write code less efficiently and these are exploited in a scenario where LoC are measured for productivity.
Here is one extremely simple example of code inflation:
for(int i = 0; i < array.length; i++)
array[i] = -1;
The above examples logically equivalent in Java. They both work. They both do the exact same thing. In C# the first could look like the following:
array = Enumerable.Repeat<int>(-1, array.Length).ToArray();
We could also write our own C# extension method to match the simpler Java method and use it throughout the code in future improving readability and maintainability.
public static void Fill(this int array, int fillValue)
for(int i = 0; i < array.length; i++)
array[i] = fillValue;
Once complete, it would be executed as follows:
This approach would lead to a couple of additional lines when it is first written ONCE and then only one line to do the same work forever after. Assuming of course that people know the extension method exists and they use it… another discussion perhaps.
One of the reasons we use modern programming languages is because they are expressive and easy to read. Even in a current modern language, older and more verbose approaches are still valid in code (to enable us to customize better approaches on our own that are not supported by the framework) and can easily be exploited by developers looking to boost their LoC written.
Counting Added LoC as a Measure of Productivity Must be Based on False Assumptions
“[Counting lines of code as a measure of productivity] presumes that each day or week or month is the same as the last day, week, or month, and that the thought stuff we actually get paid to do doesn’t matter.”
Senior Software Engineer Microsoft Research
Measuring added LoC also assumes the work completed before, after, and during the coding process to determine best/cleanest/most maintainable/efficient approaches are meaningless and that testing to verify that the code does what is was intended to do is a waste of time.
Additionally, less-experienced junior developers are always going to write more lines of code than senior people for a variety of reasons.
- Junior people often take the easiest, most brute force approach because they haven’t learned to do it better. Yet.
- Junior people are given less complex tasks to solve that can be done more quickly.
- Progressively more experienced people have additional increasing responsibilities (for example mentoring and training less experienced people, doing more code reviews, being involved in architecture/design discussions, taking on difficult roles like security guild, creating documentation, etc.
1 and 2 are arguably best solved by pair programming. Another discussion. Another time.
Counting Removed LoC as a Measure of Paying Technical Debt
“Simplicity is the ultimate sophistication.”
Leonardo da Vinci
Same as measuring added LoC, counting removed LoC drives bad behavior and can lead to developers writing code that is intentionally overcompact and difficult to read. However, in a large and unwieldy application, we want to remove lines that serve no purpose at every opportunity while maintaining the same functionality. If this were trivial, we could simply automate programming and developers would no longer be needed. Making things simpler is, simply put, not easy.
Counting LoC as a Measure of Quality
In the history of computer science, there has never been a valid correlation between LoC and quality in any programming language in existence. Check the textbooks, the internet, or anywhere else you can think of. This correlation does not exist.
The Burden of Unnecessary LoC is Non-trivial
“Measuring programming progress by lines of code is like measuring aircraft building progress by weight.”
I’ll use a slightly exaggerated example here, but it isn’t too far off, so please bear with me. Let’s assume we have two people attempting to solve a difficult problem.
- may be less experienced or expert beginner
- just get’s it “done”
- tends to solving problems hastily without concern for introducing bugs
- often works quickly and on their own without taking time for design discussion, planning, and refactoring
- may be more experienced
- cares about quality and hates bugs
- aims to understand the scope of the problem before starting to solve it
- involves others (seeking real input) to suss out design flaws and make take more complex problems to a mentor
I’ve seen real life scenarios where Persona A will solve a similar problem in 2000-3000 LoC where Persona B would solve it with 200-300 LoC. That may not seem so bad. Maybe Persona A finished their effort in less time than Persona B. Now consider, from the time this code goes into production until it is replaced/removed/refactored/decommissioned, we have to pay to maintain the code that was written. When we want to make a change in the behavior of the
Maybe Persona A finished their effort in less time than Persona B. Now consider, from the time this code goes into production until it is replaced/removed/refactored, we have to pay to maintain the code that is written. When we want to make a change in the behavior of the code or add a new feature, Persona A’s code may require days of review to understand and will also require many changes to achieve. To make a similar change to Persona B’s code, it could be understood in an hour, perhaps. The changes should take considerably less time depending on their complexity.
When we want to make a change in the behavior of the code or add a new feature, Persona A’s code may require days of review to understand and will also require many changes to achieve. To make a similar change to Persona B’s code, it could be understood in an hour, perhaps. The changes should take considerably less time depending on their complexity. Of course, this scenario is hypothetical. This is my one apology for rhetoric.
For clarity’s sake, I’m in no way arguing against hiring junior people. Fresh blood is vital for tons of reasons I won’t go into here. However, the effective incorporation of junior people must be accompanied by the correct structure and support from more experienced people in order for them to succeed. I AM against hiring expert beginners who’ve been doing this work for many years and thinks the “just get it done” approach is the best/only way.