This document provides an overview of zero-based budgeting (ZBB), outlining its key principles and steps in the process. ZBB requires managers to justify their entire budget requests from scratch each year, rather than relying on the previous year's budget. It involves analyzing all activities and ranking them based on cost-benefit analysis. Decision packages are prepared for each component of expenditure and ranked using an inverse pyramid system. The document defines important terms and components in ZBB, and emphasizes regularly scrutinizing "must" activities to avoid resource creep. It also stresses developing quality alternatives to the status quo that address key values and trade-offs.