Lean is a systematic approach to eliminating waste and maximizing value that originated at Toyota and has transformed project management across industries. At its core, Lean focuses on identifying what customers truly value and then streamlining every process to deliver it efficiently — cutting out activities that consume resources without adding value. The real power of Lean lies not in isolated tools but in its philosophy: respect for people who do the work combined with relentless continuous improvement (kaizen). Understanding the difference between value-adding and non-value-adding activities, recognizing the 8 wastes (TIMWOODS), and creating flow through pull systems fundamentally changes how teams deliver projects — faster, cheaper, and with higher quality.
What This Cheat Sheet Covers
This topic spans 16 focused tables and 94 indexed concepts. Below is a complete table-by-table outline of this topic, spanning foundational concepts through advanced details.
Table 1: The 8 Wastes of Lean (TIMWOODS)
Eliminating waste is the foundation of Lean methodology. The TIMWOODS acronym identifies eight categories of non-value-adding activities that drain resources and slow delivery. Originally seven wastes (TIMWOOD), Toyota later added an eighth — unused talent — recognizing that failing to engage people's problem-solving abilities is perhaps the most costly waste of all. These wastes compound: overproduction creates inventory, which requires transportation and motion, leading to defects and waiting.
| Waste | Example | Description |
|---|---|---|
Moving materials across warehouse when production line could be adjacent | • Any unnecessary movement of materials, products, or information between locations • adds time and risk of damage without adding value | |
Raw materials stockpiled for 3 months when weekly delivery is possible | • Excess materials, work-in-progress, or finished goods sitting idle • ties up capital, hides problems, and risks obsolescence | |
Operator walking 50 feet to retrieve tools multiple times per shift | • Unnecessary movement of people • walking, reaching, bending, or searching that could be eliminated through better layout or organization | |
Machine operators standing idle while equipment cycles complete | • Idle time when people, materials, or equipment are not moving forward • downtime between process steps or waiting for information |