Definition from Gartner
“A framework of seven types of activity that do not add value; originally defined by Toyota: overproducing — producing product before there’s a valid order; unnecessary waiting — lengthened cycle time, which reduces agility; unnecessary transportation — unnecessary transportation of material between sites; overprocessing — processes longer or more complex than necessary; unnecessary inventory — buildup of work-in-process or raw materials; unnecessary movement — inefficient workplace; layout causing extra work; and too many defects — poor process quality and too much rework”
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