Almost every production environment faces the same root causes of inefficiency. Internationally, these are known as the Six Big Losses. Understanding them means grasping the core of OEE logic – because these six categories describe where and why production time is lost.
The six big losses in production are:
Caused by technical failures, missing material, or lack of personnel. Every minute of interruption triggers follow-up costs, disrupting schedules and creating restart losses.
Product changeovers or format adjustments are part of daily operations – but their duration determines the flexibility of a plant. Even small standardizations in preparation can deliver significant time savings.
Short interruptions, often just seconds long, rarely attract attention but add up over time. Typical causes include minor irregularities such as material flow delays, sensor errors, or brief operator interventions.
Machines often do not run at their optimal speed – whether out of caution or habit. This reduces output without being immediately visible.
Every defective product consumes resources without creating value. Scrap often occurs at critical points – during startups, changeovers, or due to unstable processes.
6. Startup Losses
After downtime, many processes need time to return to stable quality. This phase is rarely fully productive.
These categories sound simple, but their interactions are complex. A changeover can lead to microstops, microstops to speed losses – and together they reduce availability. That’s why the first step is data collection: when and where do losses occur, how often, how long? Even a simple timeline makes it clear which type of problem dominates. Only then is it worthwhile to discuss root causes.
