Summary of "人生が変わるマイルールの作り方【シンプルルール2.0〜Dラボ無料版】"

Core idea

Use a very small set of situation-specific “Simple Rules” (2–5, ideally 3) to improve decision-making, execution, and coordination in complex, uncertain environments. Rules reduce cognitive load, automate desirable behaviors, and target bottlenecks rather than trying to formalize everything.

Frameworks, playbooks and explicit rule types

Six-type Simple Rules framework (two broad categories: decision rules vs. process/execution rules)

Decision rules (what to do)
- Boundary / Screening rule (“church rule”): include/exclude options to quickly narrow the universe.
- Priority rule: rank remaining options by pre-defined criteria.
- Stopping rule: decide when to stop searching/iterating and commit.
Process / execution rules (how to do it)
- How‑to / Procedural rule: step-by-step actions to execute consistently.
- Adjustment / Coordination rule: protocols to align multiple actors (who does what, and by when).
- Timing rule: when to act or when not to (scheduling, gating decisions).

Diagnosing bottlenecks (common failure modes → rule mapping)

Too much information / choice → use Boundary/Screening rules.
Can’t prioritize → use Priority rules.
Inconsistency in execution → create How‑to / Procedural rules.
Running out of time → deploy Stopping or Timing rules.

Diagnostic practice: keep a diary for about 2 weeks to identify the single activity that is failing before designing rules.

Rule design principles

Keep the number small: 2–5 rules; 3 is ideal (2 acceptable in extreme cases).
Make rules specific to the situation and the actor — don’t blindly copy others.
Tie rules directly to observable activities/decisions (actionable and testable).
Apply rules only at the bottleneck or failing area, not to everything.

Key metrics, hard numbers and practical examples

Rule count: 2–5; 3 ideal; 2 acceptable in extreme cases.
Cognitive constraint: human working memory ≈ 4 chunks (the “magic number 4”).
Practical thresholds / examples:
- Property search: screen to properties within a 20‑minute walk.
- Stopping rule: choose from the top 3 candidates.
- Wardrobe: own no more than 5 T‑shirts (stopping rule).
- Email / social media timing: check social media only 5–6 pm; reply to email three times a day (timing rule).
- Team coordination: get family agreement within 10 minutes after interior work (adjustment rule).
Pricing reference: D‑Lab annual subscription gives ~¥8,000 discount; equivalent ≈ ¥1,400/month (tax-inclusive example).

Concrete examples & case studies

Apple (Steve Jobs): simplified product lines drastically to focus and revive the company — an example of screening/prioritization driving a strategic turnaround.
Presenter’s personal examples:
- Buying clothes: screen by color (black only), prioritize comfort, stop at 5 items.
- Shopping: add items to cart and review only on Saturday morning (timing + stopping rule).
- Property search: screen by commute/walk time, prioritize sunlight vs rent, select top N candidates.
Team coordination: use explicit adjustment rules after a project milestone (who notifies whom and within what timeframe).
Behavior automation: design IF‑THEN (implementation intention) loops so desired actions trigger automatically under defined conditions.

Actionable recommendations (step-by-step)

Bottleneck diagnosis: identify the single failing activity (use a 2‑week diary if possible).
Pick one rule to start: map the bottleneck to one of the six rule types and draft a single concrete rule.
Test & iterate: apply the rule for a short period, observe results, then refine or add complementary rules (e.g., screening + stopping).
Make rules specific, measurable, and tied to actions (who, when, what).
Automate behavior where possible with “if X then Y” triggers to reduce cognitive load.
Reserve rules for friction points—don’t over-rule areas that are working to preserve creativity and flexibility.

Leadership & organizational tactics

Use compact rule-sets to align teams quickly under uncertainty—better than long manuals that aren’t used in the field.
Limit rules to what people can remember and act on in stressful situations.
Embed rules into processes and handoffs (adjustment rules) to reduce coordination costs and decision delays.
Use priority and stopping rules to reduce procrastination and decision paralysis at leadership and product levels.

Caveats & risks

Don’t copy rules verbatim from others; they must be situation- and person-specific.
Misapplied rules (too many, too abstract, or applied where not needed) can stifle creativity or fail in practice.
On AI: use AI for routine/menial tasks but retain human judgment for product, positioning, and curation—avoid cognitive offloading that erodes decision capability.

Research & mechanisms referenced

Working‑memory research: human limit ≈ 4 chunks — rationale for few rules.
Evidence that simple decision rules perform well under uncertainty (key authors: Kathleen Eisenhardt & Donald Sull — book Simple Rules).
Related research and discussions from Stanford, London Business School, Harvard Business Review and behavioral research (IF‑THEN planning).

Operational examples you can deploy today

Create a single screening rule for a recurring decision (e.g., exclude suppliers with lead time > X days).
Add a stopping rule for procurement/product development: stop scouting after top 3 vendor demos and pick the best.
Implement a timing rule for customer support: agents check inbound tickets only at three scheduled times/day; escalate urgent tickets via rule.
Draft a coordination rule for releases: deploy only if QA sign‑off + product manager confirmation occur within 1 hour of pass.

Presenters / sources

Book: Simple Rules — Kathleen M. Eisenhardt and Donald Sull.
Research / references mentioned: Stanford University; London Business School; Max Planck / related behavioral research; Harvard Business Review.
Presenter: host of D‑Lab (unnamed speaker in the video).