Reducing Resource Waste with OEE & DTM

In today’s world, more and more industries are striving towards a lean manufacturing environment. This means reducing waste, but in which area? Resource wastage can affect materials, assets or even personnel, but in which particular area do plants need to invest their efforts? This is the problem that many plants face today: “We need to reduce our resource waste, but where do we start?”

The solution can be found by using an Overall Equipment Effectiveness (OEE) and Downtime Management (DTM) System. By definition OEE is cumulative measure of three separate factors: Availability, Performance and Quality.

Availability is the measure of the time spent producing against the time available for production; performance is the ratio of actual production rate against target production rate; and quality is the ratio of good product against total product.

Downtime management refers to the ability to collect and classify downtime data from the shop floor into meaningful information that can help managers understand the root causes of production inefficiency.

OEE and other associated metrics, such as mean time between failure and mean time to repair, allow plants to make better decisions regarding where they need to invest their time and money in order to make improvements, thus unlocking the hidden potential that already exists on the factory floor.

Most of the inefficiencies in a plant can be attributed to the “Six Big Losses”. OEE and Downtime Management solutions will help identify and classify these losses while providing granularity via detailed downtime definitions and contextualization. Plants need more information than whether a machine is running or not; it is important to understand why the machine is not running.

Downtime Management can provide the exact reason for a machine stop as well as how long it was in this state, if it the status was planned and if this status is related to other statuses. Contextualization for each of the problems can be determined on both a macro and micro scale using context information like shift, order, material, production line and 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 downtime 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 on areas that 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 transparency into the production process to facilitate effective management decisions as well as provide the shop floor with the monitoring tools it needs to immediately identify inefficiencies.

OEE is a powerful tool that, when used correctly, can truly unlock the hidden potential of the shop floor. 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 decided upon and implemented for the shop floor to increase efficiency.

Afterwards the cycle of data collection begins again. After each repetition on the improvement cycle the plant’s OEE rating should increase until the target goals and world class manufacturing status are achieved.

Engineering offers solutions that address the three primary functions of OEE: Acquisition, Analysis and Visualization.

Acquisition

• Equipment status, production counters, target and design speeds as well as contextual data can be manually and automatically acquired.
• Plants can rely totally on automatic data acquisition, manual data acquisition or a mixed mode of data collection.
• Plant personnel can also supply more details for downtime.

Analysis

• Calculate standard and custom KPIs. A large selection of standard algorithms is offered e.g. OEE, Availability, Performance, Quality, MTBF, MTTR, Utilization, TEEP, etc.
• Classify downtimes via reason trees. Reason Trees are hierarchical structures that simplify the categorization of downtime).
• Manage and Analyze downtime. Downtimes can be viewed, filtered and even edited, split, merged and deleted by authorized users. This gives the plant complete control over downtime management.
• Contextualize data. All data collected is stored along with the configured contextual fields, which can be standard or custom. Contextualization makes data more meaningful; for instance, it allows the calculation of OEE for a particular production run, which can then be compared against other production runs in order to isolate problem areas. 

Visualization

• OEE Metrics and KPIs can be displayed in 3 ways, via the touch panel operator interface, via the supervisor analysis pages or via reports.
• The touch panel operator pages are optimized for high visibility and ease of use. Operators are presented with runtime date that is easy to understand. An operator can monitor performance of a line or equipment and also manually enter data or justify stops via these pages.
• The supervisor analysis pages are optimized for analysis, and offer a variety of pages that allow “slicing and dicing” of data. These pages offer extensive filtering options and allow access to all of the algorithms configured in the OEE solution.
• The OEE solution offers a set of standard reports which have drill through capability. Ad-hoc reports may also be created as required.