Systems Thinking vs Lean Six Sigma - Synergies and Dissonances

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