The Importance of Micro Stoppages over Utilization downtime
Most monitoring systems ignore micro stoppages. These Utilization-Only systems do not provide the flexibility to identify and capture micro stoppages. “The Goal,” by Eliyahu M. Goldratt and Jeff Cox, is a business novel that emphasizes the importance of optimizing the production process as a whole instead of focusing on individual parts or events.
In the manufacturing industry, maximizing efficiency and productivity is paramount. Traditionally, the focus has been capturing utilization downtime — when machines are entirely idle. This fallacy is heavily endorsed and indoctrinated by “Utilization-Only” solution providers. Since these systems have no efficient method to capture micro-stoppages, they just ignore them altogether. However, evidence proves that recording micro-stoppages is even more critical for achieving optimal performance. Here’s why:
Understanding Utilization Downtime
Utilization downtime refers to significant periods when equipment is not operating, typically due to scheduled maintenance, major breakdowns, or other interruptions. The granularity of such downtime events can be as low as five minutes. This metric has been a cornerstone of manufacturing performance analysis because:
– **Visibility**: Large downtimes are easily noticeable and often clearly impact production schedules.
– **Measurability**: Measuring and quantifying substantial idle times is straightforward.
– **Focus**: Addressing major downtimes can lead to significant immediate improvements in production capacity.
Despite its importance, focusing solely on utilization downtime can overlook numerous smaller interruptions that significantly impact productivity. These micro-stoppages, although seemingly insignificant, can add up to a substantial loss in production time.
The Role of Micro-Stoppages
Micro-stoppages are brief, often frequent interruptions that occur during the manufacturing process. They can last from a few seconds to a few minutes and are caused by minor issues such as:
– **Small equipment jams**: Temporary blockages that require quick adjustments.
– **Tool adjustments**: Minor tweaks are needed to maintain quality or precision.
– **Material replenishments**: Short pauses to load new materials or components.
– **Operator interventions**: Quick stops for operators to resolve minor issues or reset machines.
While each micro-stoppage might seem insignificant on its own, their cumulative effect can be substantial. As manufacturing managers, engineers, and analysts, your role in capturing and addressing these micro-stoppages is crucial for several reasons:
Detailed Insight into Performance:
Granular Data: Micro-stoppages provide a detailed view of machine performance and reveal inefficiencies that major downtimes might obscure. Speak to a manufacturing engineer and he is trying to address process inefficiencies, whereas production staff are focused on downtime events causing disruption on the shop floor. Both are important, but only process improvements will provide long-lasting benefits.
Root Cause Analysis: Identifying micro-stoppage patterns can help uncover the root causes of larger inefficiencies. All major downtime events can be tied to their micro-stoppage cousins. A downtime event just doesn’t occur; it is usually the result of unnoticed micro-stoppages that indicate a pending failure.
Improved Predictive Maintenance:
Trend Analysis: Regularly occurring micro-stoppages can signal impending equipment failures or the need for maintenance before a major breakdown occurs.
Preventative Actions: Early detection allows for timely interventions, reducing the likelihood of unexpected major downtimes.
Enhanced Operational Efficiency:
Process Optimization: Analyzing micro-stoppages helps fine-tune manufacturing processes, leading to smoother operations and reduced waste.
Operator Training: Understanding the frequency and causes of micro-stoppages can inform targeted training programs for operators to quickly handle and prevent minor issues.
Cost Reduction:
Minimized Disruptions: Reducing the frequency and duration of micro-stoppages can lead to a more consistent and reliable production flow, lowering operational costs.
Resource Allocation: A better understanding of micro-stoppages can lead to a more effective allocation of maintenance resources, optimizing labor and part usage.
Case Studies and Examples
- Automotive Manufacturing:
Challenge: An automotive plant experienced frequent but brief stops on its assembly line due to minor tool recalibrations.
– Solution: The plant identified that certain tools required more frequent calibration by recording and analyzing these micro-stoppages. Implementing a predictive maintenance schedule reduced these interruptions by 30%, increasing overall line efficiency.
- Food and Beverage Industry:
– Challenge: A beverage bottling company faced frequent micro-stoppages due to small clogs in the bottling line.
– Solution: Detailed recording and analysis revealed that certain bottle shapes were more prone to causing jams. Switching to a different design reduced micro-stoppages, improving throughput by 15%.
Implementation Strategies
To effectively record and analyze micro-stoppages, manufacturers should:
Invest in Technology: Use advanced monitoring systems and IoT sensors to capture real-time data on machine performance. Most monitoring systems rely on IDLE events; however, most micro stoppages are camouflaged as part of the part-to-part time. A system such as MERLIN can be configured to interpret such in-line events and capture the extension of such events beyond what the time study attributes to them. It’s easy for a system to identify acute downtime events such as IDLE, but only smart systems like MERLIN can differentiate logically with inferred material movement events.
Train Staff: Ensure operators are trained to recognize and report micro-stoppages accurately.
Integrate Data Analysis: Use data analytics tools such as MERLIN to process and interpret the collected data, turning it into actionable insights.
Continuous Improvement: Foster a culture of continuous improvement where insights from micro-stoppage data lead to ongoing process refinements.
Illustration of the Value of Identifying Micro-Stoppages Compared to Recording Accumulated Downtime
Scenario: Micro-Stoppages
Consider a scenario where a manufacturing line experiences a one-minute micro-stoppage every twenty minutes. Let’s break down the impact of these micro-stoppages over a 30-day period:
– **Micro-Stoppage Duration**: 1 minute
– **Interval**: Every 20 minutes
– **Operational Time**: 24 hours/day
– **Days in Month**: 30
**Calculations**:
- **Micro-Stoppages per Day**:
24 hours x 60 minutes / 20 minutes= 72 micro-stoppages per day
- **Total Micro-Stoppage Time per Day**:
72 micro-stoppages x 1 minute = 72 minutes (1.2 hours)
- **Total Micro-Stoppage Time per Month**:
1.2 hours/day x 30 days = 36 hours/month
- **Cost of Micro-Stoppages per Month**:
36 hours x $100 (hourly cost of production) = $3600
Scenario: Accumulated Downtime
Consider an alternative scenario where the manufacturing line accumulates 15 hours of downtime over the same period.
Calculations:
- **Accumulated Downtime**: Accumulation of IDLE (downtime) throughout the month of 15 hours
- **Cost of Accumulated Downtime**:
15 hours x 100 per hour = $1500
Comparison
– **Micro-Stoppages**:
– Total Downtime: 36 hours/month
– Total Cost: \$3600/month
– **Accumulated Downtime**:
– Total Downtime: 15 hours/month
– Total Cost: \$1500/month
Conclusion
Identifying and addressing micro-stoppages is significantly more valuable than merely recording accumulated downtime. Over a 30-day period, frequent one-minute micro-stoppages can result in a total downtime of 36 hours, costing \$3600. In contrast, recording an accumulated downtime of 15 hours costs only $1500. Accumulated downtime is the low hanging fruit, which, after operational adjustments, they are all but gone. Manufacturers can uncover hidden inefficiencies by focusing on micro-stoppages and significantly reducing operational costs. The focus on capturing and correcting process inefficiencies goes far beyond any utilization fixes. Ask any manufacturing engineer worth his salt and he’ll tell you.
While capturing utilization downtime remains important, recording micro-stoppage offers a more nuanced and comprehensive understanding of manufacturing efficiency. By focusing on these small but significant interruptions, manufacturers can enhance predictive maintenance, improve operational efficiency, reduce costs, and ultimately achieve higher productivity and reliability in their operations. Embracing this detailed approach supported by smart systems such as MERLIN ensures that no minor inefficiency goes unnoticed or unaddressed.
by Tim Smith