Σ
Sigma Testing
The quality journey of any delivery is made easy when using a simple, scalable and transparent model of quality assessment. Sigma is such a model that brings clarity in a rigorous world.
Confusion reigns when it comes to testing a product
Why are the tests needed?
What did the tests cover?
Using which build?
What was tested?
What wasn’t ?
When?
How?
These questions plague teams, stakeholders, and leaders alike.
Drawing from my experience of hybrid systems at Schindler, where automated simulations blend with real-world tower trials, Sigma Testing is a model that brings order to this frequent chaos.
Α ▸ ⋯ ▸ Ω
α ▸ β ▸ γ ▸ ⋯ ▸ ω
◈ ◇ ◇ ⋯ ◆
⁛ Aω ≡ Βα ⋰ Bω ≡ Γα etc.
Inspired by the familiar "alpha" and "beta" labels for early software versions, Sigma Testing extends the Greek alphabet into a comprehensive framework. It maps a product's journey from raw inception (A) to polished release (Ω), treating testing as an additive process.
Sigma (∑) sums layers of quality. It's a traceable path, scalable from pure software to hardware-heavy domains, ensuring everyone sees the maturity level and certification scale at a glance.
The Core of Sigma Testing: Maturity and Phases
At its heart, Sigma Testing divides the quality journey into two intertwined scales using the Greek alphabet:
Maturity Levels (Uppercase: Α, Β, Γ, ... Ω): These mark the build's overall progress. An Α (Alpha) build is the initial version—fresh code or hardware prototype, potentially claiming completeness but lacking thorough validation. As it passes testing cycles, it evolves: Αlpha becomes Βeta after basic certification, then Γ (Gamma) for deeper real-world checks, and so on, culminating in Ω (Omega), the releasable product.
Test Phases (Lowercase: α, β, γ, ... ω): Within each maturity cycle, these denote escalating test campaigns. α might be quick smoke tests, β endurance runs, γ real-scenario simulations, up to ω for full certification and transition to the next maturity level.
The beauty lies in their combination: A build at "Αβ" means an alpha-maturity version undergoing beta-phase testing, defined across teams (for example tests are all run in a virtualized environment and focus on well-delimited subareas (UI, special features, particular conditions etc.). Once it completes Αω (alpha-omega), it graduates to Β (beta maturity), ready for Βα and beyond. Not every cycle needs the full alphabet—pick what fits your context. The model is flexible, yet rigorous, answering the perennial questions: Why? What? When? How? Each phase "sums" more assurance, building confidence layer by layer.
A Real-World Example: Elevators at Schindler
In my role at Schindler, managing product development for smart elevators, which are a mix of mechanical hardware and sophisticated software, Sigma could clarify our pipeline for assessing the quality of the software we worked on, which powers every Schindler elevators:
Α (Alpha) Cycle: The freshly created new build is autonomously tested in a fully digital environment. Αα: 15-minute smoke tests for basic functionality. Αβ: 48-hour endurance runs, automated for efficiency. Success at Αω yields a Β build—certified at alpha level.
Β (Beta) Cycle: B is handed to a specialized team (the Beta-test team) which will proceed with manual testing on large simulators. Βα: Initial human-involved checks. Ββ: Extended validations. Bγ: long runs of endurance testing on specific simulators. Βω certifies it as Γ, ready for physical trials.
Γ (Gamma) Cycle: The software build is installed on real elevator towers. Γα to Γω: Tests unique to physical scenarios, including legal requirements, building "real-life" confidence.
Δ (Delta) Cycle: Focuses on edge cases—deltas from standard flows, like unusual loads and rarely used (but critical) services.
Ε (Epsilon) Cycle: Evaluation in customer sites. Εα to Εω: Real-world monitoring over months, assessing final quality. Includes final roundtable with requirements teams, development teams representatives and testing teams to manually assess final quality.
Ω (Omega): The summit—after all cycles, the build is released, traceable back through every step.
This model demystifies handoffs between teams, ensures coverage transparency, and scales: alpha cycles are autonomous and fast; later ones involve humans and hardware for depth.
Sigma provides a map
It reads from bottom left corner to the right, going up with quality evaluation| Product Maturity |
α (Basic) | β (Deep) | γ (Real) | δ (Edge) | ε (Eval) | … | ω (Certify) |
|---|---|---|---|---|---|---|---|
| Ω | Ω (Final Release – No Further Testing) | ||||||
| ... | ... | ... | ... | ... | ... | ... | ... (→ Ω) |
| Δ | Δα | Δβ | Δγ | Δδ | Δε | ... | Δω (→ ...) |
| Γ | Γα | Γβ | Γγ | Γδ | Γε | ... | Γω (→ Δ) |
| Β | Βα | Ββ | Βγ | Βδ | Βε | ... | Βω (→ Γ) |
| Α | Αα | Αβ | Αγ | Αδ | Αε | ... | Αω (→ Β) |
Assessments Sums and Landscape Clarity
Campaigns are easily identifiable, no endless discussions around vague “smoke tests” or “automated tests”. Each campaign has a unique identifier which carries the level of maturity of the whole product and the progress of its validation, and their scope is clearly defined in terms of environments, preconditions and other arbitrary sets of parameters.
Each phase adds verifiable quality, potentially quantifiable in a defined "Sigma Testing Index" (e.g., scoring coverage, duration, or pass rates). It's transparent, reducing confusion; scalable, fitting any domain. Teams see the big picture, stakeholders track progress, and leaders drive innovation with confidence.
Conclusion: Sigma Testing provides a framework, a Vision for Quality
Sigma Testing is illuminating what was always there but obscured.
Try it in your world. Quality isn't just a destination, it's a summed journey upward.
Feedback welcome at hi@loriz.io. Explore more of my insights at www.loriz.io/did/.