2.4 Lean Thinking: Reduce Waste, Focus on Essentials
Key Takeaways
- The 2020 Scrum Guide explicitly states Scrum is founded on empiricism AND lean thinking.
- Lean thinking reduces waste and focuses on the essentials.
- Lean thinking was newly emphasized in the 2020 Scrum Guide; the 2017 Guide did not name it as a foundation.
- The framework's intentional minimalism, time-boxed events, and the rule against running events that add no value are expressions of lean thinking.
- Anything that does not help the team generate value or learn is waste to be reduced, including unnecessary documentation, hand-offs, and meetings.
A 2020 Addition Worth Knowing
The 2017 Scrum Guide grounded Scrum in empiricism only. The 2020 Scrum Guide broadened the stated foundation: "Scrum is founded on empiricism and lean thinking. Empiricism asserts that knowledge comes from experience and making decisions based on what is observed. Lean thinking reduces waste and focuses on the essentials." This is one of the most reliably tested 'what changed in 2020' facts. PSM I questions sometimes ask which foundations the current Guide names, and the correct answer is both empiricism and lean thinking — a very common distractor is 'empiricism only,' which reflects the older Guide.
Lean thinking, in the Scrum context, is not a separate methodology you bolt on (it has roots in the Toyota Production System and the broader Lean movement, but the Guide does not import that machinery). It is the mindset behind why Scrum is so sparse:
- The framework defines only what is required to implement Scrum theory — nothing more.
- Events are time-boxed to create regularity, prevent waste, and protect focus.
- Each artifact carries a single commitment (Product Goal, Sprint Goal, Definition of Done) to keep attention on what matters.
- Anything that does not help create value or learning is treated as waste to be reduced or removed.
The exam framing to remember: lean thinking is the reason Scrum is lightweight. It is not optional flavor text — it is one of the two named foundations.
Why did the 2020 Guide elevate it? The authors wanted to make explicit a principle that had always shaped Scrum but was previously implicit: do less, but do what matters. Naming lean thinking gives Scrum Masters language to push back on the organizational tendency to add ceremony, gates, and reports under the banner of 'rigor.' On the exam, expect this to surface as scenarios where 'being thorough' actually means accumulating waste, and the lean-aligned move is to strip it back to essentials.
What 'Waste' Looks Like In Scrum
The Scrum Guide does not enumerate categories of waste, but the exam expects you to apply the principle to scenarios. Common forms of waste a Scrum Master helps the team and organization reduce:
| Waste | Typical symptom | Lean-aligned response |
|---|---|---|
| Unnecessary documentation | Detailed specs nobody reads | Produce only documentation that adds value |
| Hand-offs and delays | Work waiting between specialists | Build a cross-functional, self-managing team |
| Excess work in progress | Many items started, few Done | Focus on the Sprint Goal and finishing work |
| Low-value meetings | Status meetings with no decisions | Keep events purposeful and time-boxed |
| Building unused features | Output nobody actually needs | Empirically validate value each Sprint |
| Rework from poor quality | Defects found late | Strengthen the Definition of Done |
Notice how lean thinking and empiricism reinforce each other. Empiricism tells you to inspect real results and adapt; lean thinking tells you to stop doing whatever that inspection reveals is not essential. Together they keep the team's energy on outcomes rather than on ceremony, paperwork, or activity that merely looks productive. A Scrum Master who relentlessly removes waste is directly serving the framework's foundations, not 'cutting corners.'
Lean Thinking In Practice
A PSM I scenario may describe a Scrum Master deciding whether to add a process step, a new report, an approval gate, or an extra meeting. The lean-aligned instinct is to ask a single question: does this help the team generate value or learn faster? If the answer is no, it is waste — regardless of how comfortable, traditional, or 'thorough' it feels.
Concrete applications the exam may reward:
- Resist adding events or artifacts beyond what Scrum defines unless they clearly add value; the framework is intentionally minimal, and piling on artifacts to 'feel thorough' is itself waste.
- Keep each Scrum event focused on its purpose and end it when its objective is met, rather than burning the entire time-box out of habit. (Time-boxes are maximums, not quotas to fill.)
- Challenge requests for heavyweight up-front documentation or sign-off gates that delay feedback and add little value.
- Help the organization remove hand-offs that create wait time between the people doing the work and the people receiving it.
- Protect the existing events instead of replacing them: a tempting trap answer is to swap the Sprint Retrospective for a new status meeting 'to save time' — that removes inspection and adaptation and is the opposite of lean.
The enduring exam takeaway: lean thinking explains the shape of Scrum. When a question pits 'more process, more reporting, more meetings' against 'focus on what creates value and remove the rest,' the lean-aligned answer is almost always the latter.
Be careful with one boundary the exam tests: lean thinking is not a license to delete Scrum itself. Removing the Sprint Review, dropping the Definition of Done, or skipping the Retrospective to 'reduce waste' is not lean — it strips out the very inspection-and-adaptation that creates value, and it violates immutability. Lean thinking targets the waste around Scrum (redundant documents, status meetings, hand-offs, unused features), not the defined parts of the framework.
The skill being assessed is telling those two apart: prune the non-value-adding accretions, protect the lightweight core that the framework already keeps deliberately minimal.
According to the 2020 Scrum Guide, Scrum is founded on which of the following?
Complete the 2020 Scrum Guide statement: "Lean thinking reduces waste and focuses on the _______."
Type your answer below
A Scrum Master is asked to introduce a mandatory weekly 90-minute status report meeting in addition to the existing Scrum events, even though it produces no decisions. Which response best reflects lean thinking?
Which practices are consistent with the lean-thinking foundation of the 2020 Scrum Guide?
Select all that apply