Continually Improving Efficiency
What is Overall Equipment Effectiveness (OEE)?
When faced with tough economic times, manufacturers are now, more than ever, realizing the importance of capturing efficiency metrics associated with lines and plants as a whole. With the cost of energy and materials on the rise and consumer spending down, efficiency plays a vital role in improving a plant’s production process to help sustain and surpass acceptable margins. With this in mind, the question becomes, what can “the plant” do to achieve the largest and quickest return on investment? The answer is a solid Overall Equipment Effectiveness (OEE) solution, complimented by a Down Time Management (DTM) system.
OEE covers three key indicators: performance, quality and availability. OEE information, when combined with other metrics such as resource utilization, mean time between failures and speed loss, gives manufacturers an easy way to collect, categorize and use factory floor information.
Data collection and display is an essential step in the continuous effort to improve production process within the plant. Once production data is captured, it can be used to determine the root causes of inefficiencies and help determine the best solutions, unlocking the hidden potential that already exists on the factory floor. That is the purpose of a Downtime Management System.
Main Causes of Plant Inefficiency
Most of factory inefficiency can be attributed to one of six big production/OEE losses:
1. Breakdown - Downtime Loss
- Unplanned maintenance
- General breakdowns
- Equipment failures
2. Set-up & Adjustment - Downtime Loss
- Major adjustments
- Warm-up time
- Cleaning
3. Small Stops - Speed Loss
- Obstructed flow
- Component jams
- Misfeeds
4. Reduced Speed - Speed Loss
- Material Shortages
- Under design capacity
- Operator inefficiency
5. Start-up Rejects - Quality Loss
- Scrap
- In-process manage
- Incorrect assembly
6. Production Rejects - Quality Loss
- Scrap
- Rework
- In-process damage
Best Practices in Down-Time Management (DTM)
OEE/DTM solutions help identify these losses with a very fine degree of granularity. Granularity comes in the form of detailed downtime definitions and contextualization. Detailed downtime definitions are provided by the Down Time Management (DTM) part of the solution. Knowing that a machine is not running is not enough; users must know the reason why the machine is not running. DTM can provide information regarding a machine’s status including the reason for the status, length of time in that state, whether the status was planned and whether it is related to other possible statuses. Contextualization for each of the problems can be determined on both a macro and micro scale using context information such as shift, order, material, production line or machine. Problems identified on the macro scale can be further detailed on the micro level by examining the context of the information.
For example, a manger notices that the OEE performance rate on a production line is beginning to drop. Examination of the DTM information shows that one machine is being stopped by periodic small jams. These jams take 15 seconds of operator intervention to solve multiple times during a shift and over the course of a shift add up to fifteen minutes of lost production time. With this information maintenance can be scheduled for the very next downtime to bring production back up to full speed. All of this data enables the factory staff to improve areas that can cut production costs, improve on-time delivery and manage downtime to increase output/productivity and quality.
Worldwide, the accepted estimate for the average OEE level is between 45% and 60%; whereas truly efficient factories strive for a world-class rating of 85%. To reach a world-class rating, a software solution that provides clear real-time information combined with a continuous cycle of improvement is required. An effective OEE solution supplies real-time information and a clear transparency into the production process making effective management decisions possible as well as providing the shop floor with the monitoring tools needed to immediately detect inefficacies. The OEE system, however, is only a tool. In order to realize vast improvement and truly unlock the hidden potential it must be used correctly. Management should use the information it collects to identify and prioritize specific problems so they can be monitored more closely. Once a clear idea of the problem is identified then a solution can be selected and implemented for the shop floor. Afterwards, the cycle of data collection begins again. After each iteration on the improvement cycle, the OEE rating should gradually increase until the target goal of world-class manufacturing is achieved.
Engineering's Advantage
Engineering offers OEE solutions that can calculate all of the standard OEE algorithms as well as provide custom algorithms. These results are automatically displayed in a variety of easily configurable charts for easy analysis. Once the rates are calculated, the interfaces provided in the solution give users endless possibilities for displaying and comparing data. These features include advanced charting, on-the-fly custom calculations, contextualization based on production shifts/production lines and much more. Engineering also delivers solutions focused on Down Time Management or DTM. DTM monitors the individual status of equipment/production line. DTM enhances OEE by recording all significant cost metric data associated with equipment downtime in a manufacturing plant. Once the system has captured the data, it can be analyzed by managers and line supervisors to help make more informed decisions on how to lower the cost of downtime and realize greater savings. Engineering Industries eXcellence DTM solutions make it possible to capture all the necessary data, apply the right aggregation, and provide user interfaces for the visualization/analysis.
