With regards to quality, lean systems usually require: $[($Please check all that apply$).$

The use of inspectors that check quality only at the end of the process

The holding of buffer inventory to compensate for low quality products

That quality problems are dealt with as they arise, at the source

Continuous quality improvement $($kaizen$)$

The use of high levels of invertory to protect against common issues in the production process, such as machine failures, absenteeism$,$ defective supplier shipments, etc.