POKA-YOKE
Ben Ellerby, Theodo
Sofia, June 7th, 2019
bene@theodo.co.uk
https://www.linkedin.com/in/benjaminellerby/
"Poka -Yoke":
Mistake-Proofing
"Baka -Yoke":
Fool Proofing
PETROL
DIESEL
21mm
24mm
Oxy Acetylene Welding
ACETYLENE
OXYGEN
ISO 3253
Characteristics of Poka Yoke Devices
- Simple
- Cheap
- Close to mistake source
- Targeted to a particular mistake
- Based on attributes
- Obvious at a glance
Mistakes VS Defects
- Defects are mistakes that reach the customer
- Poka-Yoke aims to eliminate defects as close to the source as possible
Requirements
Doing
Review
Validation
Typing
Linting
Test Coverage
Typing
Weakly Typed
var a = 3
var b = 5
var sum = a + b
console.log(sum)
// 8var a = 3
var b = "Lean Summit"
var sum = a + b
console.log(sum)
// '3Lean Summit'Weakly Typed
var a = 3
var b = "0"
var sum = a + b
console.log(sum)
// '30'Weakly Typed
var bankBalance = 3
var depositAmount = "0"
var sum = bankBalance + depositAmount
console.log(sum)
// '30'Weakly Typed
Strongly Typed
var a: number = 3
var b: number = "0"
var sum = a + b
console.log(sum)
// '30'
Strongly Typed
"38 % Airbnb bugs preventable with TypeScript according to postmortem analysis"
Linting
Linting
var a = 3
var sum = a + b
console.log(sum)
// ?Linting
Test Coverage
100%
70%
0%
Test Coverage
"Coverage, although a flawed metric, provides a trigger to test which, along with testing standards and review, can increase quality"
- Theodo Quality Kaizen 01/01/2019
Tests Fail if Coverage Reduced
Continuous Integration
Build
Test
Report
Release
Continuous Integration
Continuous Integration
Continuous Integration
Continuous Integration
Continuous Integration
Continuous Integration
Simple
Blocking
In Doing
bene@theodo.co.uk
https://www.linkedin.com/in/benjaminellerby/
Poka-Yoke
By Ben Ellerby
Poka-Yoke
Using Poka-Yoke in Software Development Talk from the 2019 Lean Summit Bulgaria. Discussing how Poka-Yoek (mistake proofing) can apply to software development, using the examples of type checking, linting, test coverage and CI tools.
