The document discusses five common mistakes made in project accounting and time management. [1] It argues that tracking time is important for measuring productivity and costs. [2] It says that any system will not work and an easy-to-use system is needed for accurate tracking. [3] It notes the importance of tracking all time and expenses, even those not directly related to projects. [4] It emphasizes making systems simple to use but still robust. [5] Finally, it stresses the importance of consistently reviewing and acting on the tracked data.