Introduction Two shafts come off the same machine, made from the same material, by the same operator, on the same day. One measures 24.98 mm and the other measures 25.06 mm. The drawing says 25.00 mm with a tolerance of plus…

Introduction An operator measures a shaft and finds 25.03 mm against a target of 25.00 mm. He adjusts the machine down by 0.03 mm. The next part comes out at 24.96 mm, so he adjusts up by 0.04 mm. The part…

Introduction A hydraulic press stops working. The maintenance team replaces the burnt motor, the press restarts, and everyone goes back to work. Three weeks later, the same motor burns out again. The team fixed the motor. Nobody asked why the motor…

Introduction A customer returns a pump because it leaks. The quality department investigates and finds the seal was fitted incorrectly. Case closed, operator retrained. Except that is not where the problem started. Purchasing had switched to a cheaper seal supplier without…

Introduction A plant produces one lakh components a month. The rejection rate is 3 percent, which sounds small. That is three thousand rejected parts every month, plus the material, machine time, labour and inspection already spent on them. Now suppose the…

Introduction A maintenance technician gets a breakdown call. The machine is down and the whole line is waiting. He spends the next twenty two minutes looking for a 17 mm spanner, because the tool trolley has no fixed places and the…

Introduction An operator moves a box of components from a rack to his workbench forty times a shift. The rack is eight steps away. Nobody has ever questioned it, because that is where the rack has always been. One morning the…

Introduction Ask ten engineering students what the difference between quality assurance and quality control is, and about eight will say the same thing: they are basically the same. Ask the same question in a job interview and that answer will cost…

Introduction A ceramic cutting tool insert can machine hardened steel at speeds that would destroy a carbide tool. A ceramic tile in a space shuttle heat shield can glow red hot on one face while the other face stays cool enough…

Introduction Sand melts at around 1700 degrees Celsius. That is a genuinely difficult temperature to reach and hold in an industrial furnace, and for most of history it made glass an expensive luxury. Then someone discovered that adding soda ash to…