  Test-Driven Development (TDD), an agile development approach that enforces
the construction of software systems by means of successive micro-iterative
testing coding cycles, has been widely claimed to increase external software
quality. In view of this, some managers at Paf-a Nordic gaming entertainment
company-were interested in knowing how would TDD perform at their premises.
Eventually, if TDD outperformed their traditional way of coding (i.e., YW,
short for Your Way), it would be possible to switch to TDD considering the
empirical evidence achieved at the company level. We conduct an experiment at
Paf to evaluate the performance of TDD, YW and the reverse approach of TDD
(i.e., ITL, short for Iterative-Test Last) on external quality. TDD outperforms
YW and ITL at Paf. Despite the encouraging results, we cannot recommend Paf to
immediately adopt TDD as the difference in performance between YW and TDD is
small. However, as TDD looks promising at Paf, we suggest to move some
developers to TDD and to run a future experiment to compare the performance of
TDD and YW. TDD slightly outperforms ITL in controlled experiments for TDD
novices. However, more industrial experiments are still needed to evaluate the
performance of TDD in real-life contexts.
