This study investigates the multifaceted roles of artificial intelligence (AI) in enhancing productivity and consistency in software development processes. Despite AI's rapid ascent and its potential to transform software engineering, the specific productivity effects on individual developers, software development stages and the consistency of coding practices across teams remain underexplored. By analyzing the impact of AI tools like GitHub Copilot on coding efficiency and style standardization, this research aims to quantify the positive and negative consequences of AI integration across various stages of the software development lifecycle, filling a significant gap in current understanding and offering insights into the future of AI-driven software engineering.