Demystifying Change: Agile, Lean, TOC, Systems Thinking & 6-Sigma (Part I)

There’s a world of different change methodologies out there and it’s easy to be overwhelmed and unable to choose. For each one there’s an army of consultants ready to tell you theirs is the best.

The reality is very different: every methodology has its strengths and weakness. They each have different goals and suitability for different environments. The ideal solution is almost always a combination of approaches, but you can’t know which combination unless you understand how they work.

So if you want to raise your understanding and be able to make better choices and keep those consultants on their toes, please read on.

In this short series, we’ll explore how these different methodologies work and highlight their key strengths, weaknesses, differences and their suitability and applicability to different types of environment.

Which Methodologies?

Before we dive into the detail, let’s stand back and compare some common methodologies with their traditional Change Management alternative.

The methodologies we’ll cover will be:

Agile – An umbrella term for a group of methodologies and tools developed principally from software development but which have general application to products and services

Lean – An umbrella term for a group of methodologies and tools developed principally from manufacturing production but with wide application to services and product development

Theory of Constraints (TOC) – A change methodology for tackling the biggest constraint first developed principally from manufacturing but with wide application to services and products

Systems Thinking – An umbrella term for methodologies that effect change by dealing with the complete “system”

Six Sigma – A change methodology for eliminating defects and increasing standardisation principally developed from manufacturing but with applications elsewhere

Why this set? Because they are the most common ones you are likely to encounter.

Change Methodologies Compared

Let’s directly compare and contrast these six different methodologies (including traditional change management alternatives):





Theory of Constraints

Systems Thinking

Six Sigma


Deliver on Time and Budget

Deliver Value Early and Often

Maximise Flow of Value

Maximise Throughput

Service Demand Perfectly

Maximise Quality & Predictability

Example Method

Prince2, PMBOK, CMM, ISO9000


Kanban, Toyota Production System

Theory of Constraints

Vanguard Method

Motorola 6-Sigma, TQM

World View



Internal & External

(team, features and users)

Internal & External

(flow, value)


(constraints, throughput)

Internal & External

(whole system)



Economic Theory

Economy of Scale

(bigger is better)

Economy of Time

(faster is better)

Economy of Flow

(more value with less waste is better)

Economy of Capacity

(higher capacity is better – Throughput Accounting)

Economy of Demand

(it’s only better if customers find it is better)

Economy of Variation

(more standardisation and fewer defects are better)

Organising Unit

Project or Programme

Feature or Feature Group

Process or Processes

Constraint (one at a time per process)

Customer Segment or Slice of Demand


Decision Model


(leaders dictate)


(the team dictate)


(the needs of value & flow dictate)


(the needs of the constraint dictate)


(best way to meet customer needs dictate)


(the needs of the process dictate)




Value Streams


Customer Needs

Process Variability

Principal Tool

Planning and Reporting


Visual Work Management

Study Constraints

Study Demand

Statistical Process Analysis

Planning Approach


Up-front detailed plans before works starts with regular updates


Plan each delivery iteration once only at its start


Instead of planning design and try small experiments to increase flow


Plan cycle steps: Identify, Exploit, Subordinate / Synchronize, Elevate


Study demand and experiment to improve delivery


Plan for each Define-Measure-Analyse cycle

Delivery Strategy


(big bang)




Variable Cyclic

(for each constraint)

Variable Cyclic

(for each slice of demand)

Variable Cyclic

(for each process)

Delivery Cadence


(typically years or many months)


(typically weeks to a month)


(typically days to weeks)


(typically weeks to a month)


(typically weeks to a month)


(typically weeks to a month)

Typical Lifecycle


A sequence of phases (or sequentially-overlapping): Specify, Design, Implement, Deliver


Variable number of fixed short iterations (typically weeks) each containing a very short Specify, Design, Implement, Deliver cycle


Typically daily, weekly and monthly cycles reviewing value & flow using visual dashboards, implementing and monitoring changes


For each constraint on each process: Identify, Exploit, Subordinate / Synchronize, Elevate Performance


For each slice of demand:  Check, Plan, Do or Plan, Do, Check, Adjust (or similar)


For each existing process: Define, Measure, Analyze, Improve, Control.  For new processes: D, M, A, Design, Verify.

Typical Outcome Measures

Progress (time & budget), KPIs and Targets

Value Delivery Rate (per iteration), Burn Up/Down Charts.

Value Delivery Rate (per time-period), Cycle Time, Lead Time, Right-First-Time and CFDs

Throughput Accounting Throughput, Productivity, ROI, Investment, Operating Expense, Net Profit

Delivery vs Demand, Cycle/Lead Times and Failure Demand levels

Statistical Targets and Production Measures

Learning Tools & Cadence

Post-project Review

(typically months to years, if at all)


(typically weekly or monthly)

Continual Learning

(daily, weekly, monthly cycles)

Each Constraint / Production Cycle

(typically days to weeks)

Each Demand / Delivery Cycle

(typically days to weeks)

Each Process / Production Cycle

(typically weeks to months)

Optimisation Strategy

Spend More, Add People, Reduce Quality

Increase Value Delivery, Reduce Delays

Increase Value Delivery &  Better Prioritise, Eliminate Waste

Increase Throughput, Eliminate Constraints

Increase Value Delivery, Reduce Delays, Eliminate Failure Demand

Increase Quality, Reduce Variation

Inventory Focus



Not considered (highly likely to increase due to big-bang approach)

Implicitly Reduce

By-product of short iterations is reduced inventory

Explicitly Eliminate

Works to identify and explicitly remove all inventory

Explicitly Maintain Ideal

Maintain ideal inventory levels to maximise throughput

Explicitly Reduce

Reduced to the best balance to service demand as needed

Generally None

Not normally considered unless critical to specific process

For now just feast your eyes on this big picture and think about what this means for your organisation. In the next article(s) in this series, we’ll explore each of these aspects in more detail.

Good luck navigating your way through the methodology minefields!

Posted in Agile, Kanban, Lean, Methodologies, Scrum, Six Sigma, Systems Thinking, Theory of Constraints.

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