Measuring productivity in software development is a challenging task, according to Martin Fowler. He argues that current methods, such as lines of code and function points, are flawed and do not accurately reflect an individual's or team's output. Instead, he suggests that true productivity should be measured by the delivered business value. This perspective highlights the importance of considering the broader impact of software development on the organization and its customers.

Source: https://martinfowler.com/bliki/CannotMeasureProductivity.html