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Showing posts from March, 2026

Useful links

 Question bank and books and solution. https://docs.google.com/spreadsheets/d/1ULmo4GUDq8b2AUixlPgzIHzyaThmGq82VfUG2Z0jhxs/edit?usp=sharing

Theories of Accident Causation

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Theories of Accident Causation I. Introduction: Framing Accident Causation When investigating occupational injuries, efforts to prevent accidents are heavily shaped by the assumptions we make about how they occur. Historically, there have been two broad paradigms in understanding accident causation: Blaming the Victim: Early theories (such as the concept of "accident-proneness" from the 1920s) assumed that certain workers were inherently susceptible to accidents, leading to the conclusion that safety could be managed by screening out "unsuitable" workers. Other views within this paradigm blamed worker apathy, ignorance, or "macho" risk-taking behaviors ( Occupational Health and Safety in Construction Project Management , pp. 120-122). Blaming the System: Modern alternative explanations view accidents as complex system failures. This paradigm recognizes the impact of the social relations of production (e.g., pressure to meet deadlines), the physical/tec...

Six Sigma

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To understand Six Sigma, let's use a simple analogy: a casual weekend golfer versus a professional golfer. If you watch a casual player tee off, their shots exhibit high "scatter"—one ball slices into the woods, the next hooks into the water, and occasionally, one lands perfectly on the fairway. Their swing is full of uncontrolled variables. A professional golfer, however, has refined their mechanics to eliminate unwanted movements. They hit the fairway consistently, time after time, because they have virtually eliminated the variation in their swing. In construction, "reducing variation" means doing things the exact same, correct way every single time, regardless of who is performing the task [ Quality Management in Construction Projects, Second Edition , p. 88]. Variation is the enemy of quality; it leads to defects (like a cold joint in concrete or out-of-plumb walls), and defects lead to unhappy clients and costly rework. The goal of Six Sigma is to identif...

Cause-and-effect (Fishbone) diagram

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1. The Layman’s Intro: The "Car Won't Start" Analogy Understand the core logic of this tool using a simple, everyday analogy: troubleshooting a car that won't start. Imagine you wake up, get into your car, turn the key, and hear nothing but a click. The car not starting is the "Effect" (the problem). If you were to draw this, "Car Won't Start" goes in a box at the far right, like the head of a fish. Instead of randomly guessing what is wrong, you brainstorm major categories of potential issues to form the "bones" of the fish: Electrical: Is the battery dead? (If yes, why? Left the headlights on). Fuel: Is the gas tank empty? Is there a leak? Mechanical: Is the starter motor broken? Human Error: Is the car not actually in "Park"? The Fishbone diagram visually organizes your troubleshooting process. It forces you to look at every possible category of failure rather than jumping to the most obvious conclusion. By repeated...