1.2 History & Evolution of Six Sigma
Key Takeaways
- Six Sigma was developed at Motorola in 1986 by reliability engineer Bill Smith (the 'Father of Six Sigma') with executive sponsorship from CEO Bob Galvin.
- Bill Smith's empirical breakthrough proved that products requiring factory rework or repair experienced significantly higher early-life failure rates in the field.
- Dr. Mikel Harry founded the Six Sigma Academy in 1994, codifying the DMAIC problem-solving cycle and introducing the martial arts belt hierarchy.
- Jack Welch launched an enterprise-wide Six Sigma deployment at General Electric in 1995, linking 40% of executive bonuses to quality goals and driving over $4.4B in net savings.
- Modern Lean Six Sigma synthesizes Lean's focus on waste elimination (Muda) and process speed with Six Sigma's focus on variation reduction and statistical capability (3.4 DPMO).
1.2 History & Evolution of Six Sigma
Executive Summary: Six Sigma was created in 1986 at Motorola by reliability engineer Bill Smith and CEO Bob Galvin to counteract catastrophic market-share losses against Japanese electronics competitors. Built on the insight that internal factory rework breeds latent customer defects, Six Sigma replaced reactive end-of-line inspection with statistical process control targeting 3.4 defects per million opportunities (DPMO). Codified by Dr. Mikel Harry into the martial arts belt structure and scaled globally by Jack Welch at General Electric in 1995, the discipline has evolved into modern Lean Six Sigma (LSS), combining process velocity with statistical precision.
The Crisis in American Manufacturing (1970s–1980s)
During the post-World War II decades, American industrial manufacturing enjoyed uncontested global supremacy. High production volume was prioritized over process capability, and quality control was relegated to downstream inspection departments whose primary role was to screen finished goods and discard or rework nonconforming units.
By the late 1970s, this paradigm collapsed when Japanese manufacturers—guided by the teachings of American statistical pioneers Dr. W. Edwards Deming and Dr. Joseph M. Juran—entered Western markets with automobiles, consumer electronics, and semiconductors that displayed extraordinary reliability at competitive prices.
A watershed event occurred in 1974 when Japanese conglomerate Matsushita Electric Industrial Co. acquired Motorola's Quasar color television manufacturing plant in Franklin Park, Illinois. Using the identical American frontline workforce, union contracts, and physical factory facilities, Matsushita completely overhauled operating procedures, standard work, and process controls. Within three years, Matsushita slashed assembly defects from 150 defects per 100 TV sets down to fewer than 4 defects per 100 sets, while cutting customer warranty repair costs by over 90%.
This dramatic turnaround eliminated the prevailing excuse that poor quality was caused by frontline worker carelessness; it demonstrated conclusively that quality deficiencies were systemic, stemming from unmanaged process variation and defective managerial operating philosophies.
The Motorola Genesis: Bill Smith & Bob Galvin (1981–1988)
In response to mounting competitive threats, Motorola Chief Executive Officer Bob Galvin issued an unprecedented company-wide challenge in 1981: Motorola was mandated to achieve a tenfold (10x) improvement in quality across all operating divisions over a five-year window.
Motorola's Quality Transformation Timeline
1974: Matsushita acquires Quasar plant; proves American workers can produce world-class
quality when provided with capable, variation-controlled processes.
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1981: CEO Bob Galvin issues enterprise mandate for a 10x quality improvement in 5 years.
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1986: Reliability engineer Bill Smith discovers the direct correlation between factory
rework and field failures; Six Sigma is officially formulated and launched.
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1987: Motorola establishes the 3.4 DPMO standard (incorporating 1.5σ drift) across all lines.
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1988: Motorola receives the inaugural Malcolm Baldrige National Quality Award.
Bill Smith: The Father of Six Sigma
Bill Smith, an experienced reliability and quality engineer within Motorola's Land Mobile Products Sector, conducted comprehensive statistical investigations into field warranty data for mobile communications devices. His findings uncovered a startling, counterintuitive reality:
The Smith Reliability Discovery: Products that underwent internal rework, component re-soldering, or manual adjustment during factory assembly experienced dramatically higher failure rates during customer use than units manufactured correctly the first time—even though all units successfully passed identical final inspection checks.
Traditional manufacturing dogma held that as long as an assembly passed final quality inspection, its past production history was irrelevant. Smith demonstrated that internal rework created microscopic physical stresses, latent solder micro-fractures, and thermal degradation that escaped factory test benches. When deployed in customer environments under ambient temperature fluctuations and vibration, these latent defects manifested as premature product breakdowns.
Smith coined the concept of the "hidden factory"—the unmeasured network of rework loops, scrap bins, and technician re-testing that consumed up to 30% of plant operating capacity. He asserted that quality cannot be inspected into a product; quality must be engineered into the underlying processes by eradicating variation so that components are manufactured correctly on the initial pass.
Partnering with CEO Bob Galvin, Smith formulated the Six Sigma Quality Program in 1986. Together, they established a mathematical process capability target of Six Sigma—defined as 3.4 defects per million opportunities (DPMO) when accounting for an empirical 1.5-sigma long-term process mean shift. Through this transformation, Motorola eliminated hundreds of millions of dollars in waste and won the inaugural Malcolm Baldrige National Quality Award in 1988.
Dr. Mikel Harry & The Six Sigma Academy (1994)
While Bill Smith established the empirical and reliability foundations of Six Sigma, Dr. Mikel J. Harry transformed the discipline from an engineering tool into a standardized, repeatable corporate deployment architecture. While serving at Motorola's Government Electronics Group, Harry authored foundational technical papers on advanced statistical tolerancing and process characterization.
In 1994, Dr. Harry founded the Six Sigma Academy (SSA) in Scottsdale, Arizona. He made two monumental contributions to the methodology:
- The DMAIC Roadmap: Harry formalized the 5-phase problem-solving architecture—Define, Measure, Analyze, Improve, Control—providing project teams with a universal step-by-step framework to diagnose and optimize complex business processes.
- The Martial Arts Belt Hierarchy: Harry created the tiered belt organizational structure (Master Black Belt, Black Belt, Green Belt, Yellow Belt). By borrowing martial arts nomenclature, Harry established visible professional credentials, clear competency tiers, and dedicated change-agent responsibilities that transformed how companies deployed technical talent.
ABB, Allied Signal & General Electric: The Scaling Era (1990s)
In the early 1990s, former GE executive Larry Bossidy introduced Six Sigma at AlliedSignal (now Honeywell), achieving rapid margin expansion and proving that Six Sigma generated substantial bottom-line financial gains.
Observing Bossidy's commercial success, Jack Welch, Chairman and CEO of General Electric (GE), launched Six Sigma across the entire GE conglomerate in late 1995. Welch did not treat Six Sigma as a peripheral quality initiative; he established it as GE's core corporate operating system.
Jack Welch's Cultural Mandates at GE
┌───────────────────────────┬───────────────────────────┬───────────────────────────┐
│ Executive Compensation │ Promotional Prereq │ Full-Time Dedication │
│ 40% of executive annual │ Green Belt training made │ Top-tier talent assigned │
│ incentive bonuses tied │ a mandatory gate for any │ to 2-year full-time │
│ directly to Six Sigma │ managerial promotion │ Black Belt leadership │
│ project financial gains │ across all business units│ rotations │
└───────────────────────────┴───────────────────────────┴───────────────────────────┘
Welch instituted uncompromising policies that forced cultural adoption throughout GE's global footprint:
- Executive Bonus Alignment: A full 40% of executive annual incentive bonuses were linked directly to Six Sigma implementation milestones and verified cost reductions.
- Management Promotion Gate: No employee could be considered for management or professional advancement without completing at least Green Belt training.
- Full-Time Dedication: Rather than assigning project leadership to low-demand staff, Welch mandated that top-performing high-potential leaders be pulled from regular roles to serve two-year, full-time rotations as Black Belts.
Between 1995 and 2000, General Electric invested over $1 billion in Six Sigma training, infrastructure, and project execution. In return, GE reported over $4.4 billion in net cost savings and over $12 billion in operating margin improvements. Crucially, Welch proved that Six Sigma was not confined to industrial assembly lines: GE applied the framework with equal financial success to GE Medical Systems, GE Aircraft Engines, NBC Broadcasting, and GE Capital credit card processing.
Evolution into Modern Lean Six Sigma (LSS)
Chronological Evolution of Six Sigma
1986: Hardware Manufacturing (Motorola)
Focus on electronic assembly, soldering yields, component tolerancing.
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1995: Enterprise Scaling (General Electric & AlliedSignal)
Focus on cross-business deployment, customer CTQs, operating margins.
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2000s: Healthcare & Financial Services
Focus on clinical safety, billing accuracy, loan cycle time, transactional flow.
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Present: Integrated Lean Six Sigma (LSS)
Synthesis of Lean process speed/waste reduction with Six Sigma variation control.
As organizations recognized that administrative, transactional, and service operations suffered from the same variation and defect dynamics as assembly plants, Six Sigma expanded rapidly:
- Healthcare Systems: Applying DMAIC to eliminate medication administration errors, standardize surgical instrument preparation trays, reduce hospital-acquired infections (HAIs), and compress emergency department patient dwell times.
- Banking & Financial Services: Reducing mortgage and loan origination cycle times, eliminating credit transaction reconciliation discrepancies, and standardizing regulatory anti-money laundering (AML) audit controls.
- The Lean Six Sigma Synthesis: During the 2000s, practitioners recognized that Six Sigma and Lean manufacturing (derived from the Toyota Production System) were complementary rather than competing disciplines. Lean focuses on process speed and waste elimination (Muda), while Six Sigma focuses on process consistency and defect elimination. Today, Lean Six Sigma combines the velocity of Lean with the statistical precision of Six Sigma.
Lean vs. Six Sigma Comparison
| Operational Dimension | Lean Methodology | Six Sigma Methodology |
|---|---|---|
| Pioneering Organization | Toyota Motor Corporation (Taiichi Ohno) | Motorola Inc. (Bill Smith & Bob Galvin) |
| Core Strategic Goal | Eliminate process waste (Muda) and accelerate flow | Reduce process variation and eliminate defects |
| Primary Problem Solved | Delays, queues, bottlenecks, and excess inventory | Output inconsistency, out-of-spec defects, and rework |
| Key Metric | Lead time, process cycle efficiency, takt time | Sigma level, DPMO, process capability ($C_{pk}$) |
| Primary Toolset | VSM, 5S, Kanban pull systems, Poka-Yoke, Kaizen | DMAIC roadmap, Gage R&R, hypothesis tests, SPC, DOE |
| Deployment Synergy | Lean provides velocity; removes non-value-added steps | Six Sigma provides precision; stabilizes remaining steps |
The Seven Common Six Sigma Principles (CSSC's Named List)
Chapter 1 of the CSSC manual names seven principles an organization integrates into leadership styles, process management, and improvement work. They appear as a list, so expect them as list-recall items.
| Principle | What CSSC Says It Means |
|---|---|
| 1. Customer-Focused Improvement | Six Sigma does not improve for the sake of driving up sigma levels. Understanding what the customer actually wants (via Voice of the Customer) lets an organization add features customers will pay for, prioritize development against current needs, generate ideas from feedback, read market trends, identify areas of concern, prioritize by how customers perceive problems, and test solutions before spending on them. |
| 2. Value Streams | The sequence of all items, events, and people required to produce an end result. CSSC's illustration is serving a hotdog: suppliers, ingredients, a cooking procedure, a pot, tongs, a cook, a plate, and each person who assembles and serves it. Drawing that sequence pictorially produces a value stream map, which exposes concerns, waste, and improvement opportunities. |
| 3. Continuous Process Improvement | An organization that fully adopts Six Sigma never stops improving. Move a process from 4 sigma to 4.4 sigma and you then look for the next increment, always heading toward 99.99966% accuracy while maintaining other goals such as financial stability. |
| 4. Variation | Every process contains inherent variation. Reducing it is one route to continuous improvement — CSSC's pizzeria example walks from "use one cup of cheese" to measuring cups to a flat spatula scraping the rim, each step cutting variation further without ever reaching zero. |
| 5. Removing Waste | Removing items, actions, or people unnecessary to the outcome reduces processing time, opportunities for errors, and overall costs. CSSC is explicit that the concept of waste comes from Lean Process Management, not from Six Sigma itself. |
| 6. Equipping People | Improvements are temporary unless the employees who work the process daily are equipped to monitor and maintain them. The two-pronged pattern: an improvement team defines, plans, and implements; that team then equips daily staff to control and manage the improved state. |
| 7. Controlling the Process | Six Sigma often addresses processes that are out of statistical control. The goal is to bring the process back into control and then use measurement and statistical tools to keep it there — with hands-on employees trained to use the controls. |
The Five Challenges of Six Sigma
The same chapter names the obstacles that stand between a deployment and results. Six Sigma is often viewed as expensive or unnecessary, especially by small and mid-sized organizations.
- Lack of support. Six Sigma needs buy-in at all levels. Common barriers: leaders unfamiliar with the process; leaders who back an initiative then lose interest before it completes; staff fearful of change, particularly where past change hurt employees; employees who believe improvements will make them obsolete or their jobs harder; and department heads who champion only their own processes and will not think big-picture.
- Lack of resources or knowledge. Lack of knowledge about how to use and implement Six Sigma is the first issue small and mid-sized companies hit. Smaller businesses cannot always afford dedicated continuous-improvement staff — though CSSC notes this does not have to be a barrier, since available training makes it increasingly possible to use the tools without an in-house expert.
- Poor project execution. A sound methodology badly run produces no result and damages appetite for the next project.
- Data access issues — inconsistent access to valid statistical data.
- Concerns about using Six Sigma in a specific industry. The belief that the method suits manufacturing but not one's own sector.
[!NOTE] CSSC's counter-example. Ideal Aerosmith, a manufacturing and engineering company in Minnesota, was skeptical of both Six Sigma and its cost. It implemented anyway and saw worthwhile results within 18 months: production up 25%, profits up 5% in the first year, and timely deliverables up 30%. Expect this cited as evidence that cost skepticism is answerable.
What Distinguishes Six Sigma from Earlier Quality Models
The seven CSSC principles above describe what Six Sigma does. This shorter list answers a different question that scenario items like to pose: given TQM, Lean, and BPR all existed, what does Six Sigma add? Four things:
- Focus on Defect Prevention Rather than Detection: Traditional quality systems inspect products at the end of the line, sorting conforming units from scrap. Six Sigma moves upstream, identifying and standardizing the vital process inputs to prevent defects from ever occurring.
- Statistical Process Capability (3.4 DPMO): Setting a mathematical standard of 3.4 defects per million opportunities (representing a 99.99966% success rate), ensuring processes operate six standard deviations away from customer specification limits.
- Empirical, Data-Driven Culture: Subjective managerial opinions, gut feelings, and untested assumptions are replaced by verified statistical data. As Dr. W. Edwards Deming famously quipped, "In God we trust; all others must bring data."
- Customer-Centric Quality Focus: Quality is defined exclusively through the eyes of the customer. The Voice of the Customer (VOC) is translated into measurable Critical to Quality (CTQ) specifications, ensuring improvement projects align with customer value.
Realistic Industry Scenario
A commercial avionics supplier experiences a 4.2% field return rate on digital flight displays due to intermittent circuit board failures. The plant manager proposes adding five additional quality inspectors at final pack-out to catch defective displays before shipment.
A newly hired Green Belt references Bill Smith's Motorola research to challenge this proposal. The Green Belt demonstrates that the displays failing in the field had all passed final pack-out inspection after undergoing manual re-soldering touch-ups in the rework department. By tracking the "hidden factory," the Green Belt proves that the wave soldering machine's preheat temperature fluctuated by $\pm 25^\circ\text{C}$, creating brittle solder joints. Rather than spending $300,000 annually on extra inspectors, the plant installs closed-loop thermal controllers on the soldering machine, eliminating the root cause of rework. Internal rework drops to zero, and field returns decline by 94% within six months.
Critical Exam Traps to Avoid
- Trap 1: Confusing the Pioneers — Believing Jack Welch or Dr. Mikel Harry created Six Sigma. Bill Smith is universally recognized as the Father of Six Sigma; Bob Galvin was the executive sponsor at Motorola, Mikel Harry codified the belt curriculum, and Jack Welch scaled it across General Electric.
- Trap 2: Confusing Lean with Six Sigma Origins — Stating that Six Sigma originated at Toyota. Toyota developed the Toyota Production System (Lean); Motorola developed Six Sigma in 1986.
- Trap 3: Viewing Final Inspection as a Six Sigma Tool — Believing inspection stations are encouraged in Six Sigma. Inspection is a non-value-added activity that detects defects after costs have been incurred and fails to catch latent defects.
- Trap 4: Treating Lean and Six Sigma as Mutually Exclusive — Treating Lean and Six Sigma as competing systems. The modern standard is Lean Six Sigma, where Lean eliminates non-value-added delays and Six Sigma reduces process variation.
A continuous improvement director is delivering a presentation on the history of quality management to executive leadership. Who is universally recognized as the 'Father of Six Sigma', and what fundamental discovery led to the methodology's creation?
Which of the following statements best characterizes the fundamental philosophical distinction between Six Sigma and traditional quality control inspection models?
During the mid-1990s, General Electric achieved multibillion-dollar financial returns through Six Sigma. Which organizational policy instituted by CEO Jack Welch was most instrumental in driving enterprise-wide adoption of Six Sigma throughout GE's corporate culture?