Waste is seen in many different forms in manufacturing. Some of these wastes include physical, time and talent.
Physical waste is anything that is left over from the process that has to be discarded, recycled or sold. For every process, there is an expected amount of waste that is unavoidable. However, the waste that we will focus on is the excess waste that is produced because of equipment or process reliability issues. There are many processes that are a one-shot process, where if it is interrupted during the process, all of the materials become waste.
Time waste also directly relates to equipment and process reliability. Any time that the system is down for unplanned maintenance, that means there is extra time required to make up the work, idle manpower and manpower required to correct the deficiency. In many cases, the extra time required to make up the work falls into overtime or extra shifts.
Talent waste is the use of time and education to repair or correct process or equipment failures. There will always be the need for the use of talent to fix failures. The real loss is when the failures are preventable and nothing is being done to change the situation. The talent used to fix unnecessary equipment failures can be utilized to improve the process and equipment.
Any angle from which you look at reliability will reveal that it is a necessary function to be a good steward of resources.