Muda is waste: activity that consumes resources without producing anything the customer would pay for. The conventional grouping is eight types.
- Transporte — deslocar material que não precisava de ser deslocado
- Inventário — stock além do que o fluxo exige
- Movimento — pessoas a deslocarem-se desnecessariamente para realizar o trabalho
- Espera — trabalho parado entre etapas
- Sobreprodução — produzir mais, ou antes, do necessário
- Sobreprocessamento — fazer mais do que aquilo que o cliente valoriza
- Defeitos — trabalho que precisa de ser corrigido ou descartado
- Talento não aproveitado — capacidades que ninguém aproveita
Overproduction is usually treated as the worst because it manufactures the others: too much output becomes inventory, which needs transport, which conceals defects until they are expensive.
Not everything without customer value is waste to remove. Regulatory inspection and safety checks add nothing the customer would pay for and cannot go — the working distinction is between waste, which is a target, and necessary non-value-adding work, which is a constraint to keep small.
Waste-hunting also has a failure mode of its own. Eliminating waste at a step that is not the constraint changes nothing about what the system produces, and a team asked to find waste will always find some.
