## Synergies
### Emphasis on Root Cause and Continuous Improvement
- **Lean Six Sigma**: Uses structured tools (e.g. 5 Whys, fishbone diagrams, DMAIC) to diagnose and fix root causes of variation or waste.
- **Systems Thinking**: Focuses on uncovering deep, systemic causes of recurring problems, often hidden in structures or mental models.
Both aim to go beneath the surface and address the **real causes** rather than superficial symptoms.
### Process Orientation
- **Lean Six Sigma**: Views the organisation as a collection of processes to be measured and improved.
- **Systems Thinking**: Explores how processes interact across departments, teams, and time to produce outcomes.
Both seek to understand and improve how things flow through a system.
### Data-Driven Decision Making
- **Lean Six Sigma**: Relies heavily on data, metrics, and statistical analysis to justify decisions.
- **Systems Thinking**: Uses data as part of feedback loops and system models to understand behaviour over time.
Evidence matters — both approaches reject intuition-only decision-making.
### Shared Language of Systems
- **Lean Six Sigma** uses concepts like inputs/outputs, variation, and control limits.
- **Systems Thinking** uses stocks/flows, feedback, and delay.
Both treat organisations as **systems** that behave according to structure and logic — not randomness.
## Dissonances and Tensions
### Scope and Perspective
- **Lean Six Sigma**: Focuses on tightly scoped processes within defined boundaries.
- **Systems Thinking**: Challenges boundaries, asking how systems connect and what sits upstream or downstream.
Lean Six Sigma may optimise a single process in a way that damages the wider system.
### Time Horizon
- **Lean Six Sigma**: Prioritises short- to medium-term gains, typically within a 3–6 month project window.
- **Systems Thinking**: Considers long-term dynamics, time delays, and unintended consequences.
A solution may show positive short-term metrics but undermine resilience or sustainability over time.
### Nature of Change
- **Lean Six Sigma**: Treats change as manageable, structured, and usually linear (define → measure → analyse → improve → control).
- **Systems Thinking**: Sees change as dynamic, emergent, and often unpredictable.
Systems thinking may resist "projectised" interventions that don’t address systemic feedback or complexity.
### Nature of Knowledge and Insight
- **Lean Six Sigma**: Prefers quantifiable data and clear measurement systems.
- **Systems Thinking**: Integrates qualitative insight, mental models, and multiple stakeholder perspectives.
Not all important dynamics can be measured — systems thinking might prioritise insight where Lean Six Sigma demands evidence. Improvements in data don’t always translate to improvements in experience or outcomes.
### Control Orientation vs Adaptive Response
- Lean Six Sigma is rooted in **control**: reduce variation, implement standard work.
- Systems Thinking often embraces **variability** as a natural part of complex systems.
Over-controlling a system can make it brittle or resistant to change.
## Using them together
| Systems Thinking Can Help Lean Six Sigma By... | Lean Six Sigma Can Help Systems Thinking By... |
| --------------------------------------------------------------- | ----------------------------------------------------------- |
| Exposing systemic constraints beyond the project scope. | Turning insights into structured, deliverable improvements. |
| Preventing local fixes that create wider issues. | Providing robust tools for analysis and intervention. |
| Emphasising long-term system resilience and unintended effects. | Ensuring accountability and measurable outcomes. |
| Encouraging reflection on assumptions and mental models. | Driving implementation discipline and control. |