Not every company has a robust, disciplined data analysis culture. Informal exploratory analysis is common and very likely to lead to overconfident decisions or claims that can waste substantial time and money. Writing a detailed statistical analysis plan at the outset provides greater confidence in results and reduces the likelihood of overfitting, or inflation of type I error. Statistical analysis plans can control false discovery rate, appropriateness of methodology, provide testable hypotheses, clear audit trail and guidance that your internal data science team can use for future work.