Retrofitting Legacy Equipment: How a 1990s Filler Was Digitized for OEE Gains

In today’s fast-paced world, companies look for ways to boost efficiency and productivity. One key method is updating older machinery. This article tells the story of how a 1990s filler was modernized to improve Overall Equipment Effectiveness (OEE).

Updating old systems can bring big benefits. By adding new tech, businesses can see:

• Increased efficiency: Faster processes mean less downtime.
• Cost savings: Better performance can cut down on costs.
• Improved quality: New systems often make products more consistent.

The story of digitizing this filler shows the power of innovation in manufacturing. It proves that even old machines can become valuable again with the right updates.

Plant Context and Problem Statement

In manufacturing, old equipment is key but often holds back progress. A 1990s rotary liquid filler in a U.S. food plant is a prime example. Despite being mechanically good, it causes a lot of downtime, losing 11% of its time each shift.

The filler’s problems lead to a lot of waste, with over 4% of products being thrown away. This not only slows down production but also raises costs. The risk of a major failure is high because parts for the original parts are no longer made.

This filler is like a mystery box. It doesn’t connect to the internet or collect data automatically. Changes are made based on notes and the memories of long-time workers. The plant manager faces a tough choice: spend millions on a new machine or try a legacy retrofit to get more out of the old one.

The need to act is clear: make the asset digital to boost efficiency, cut waste, and lower spare parts risks. This way, the plant can keep production going and make the old equipment better without spending too much.

Diagnostic Phase: failure modes, controls obsolescence, data gaps

In the diagnostic phase, we found several big problems with the machinery’s performance. A team worked hard for 72 hours to really understand these issues. They looked at every failure from the last 18 months, using logs and maintenance records.

This work turned old paper records into a useful database. It gave us important insights.

The main problems were in three areas. First, the old servo indexing system had intermittent faults. Second, the Allen-Bradley SLC 500 processor was failing and hard to find. Lastly, there were no sensors on key parts like the main drive motor and fill nozzles.

This lack of sensors made it hard to track performance accurately.

Controls obsolescence was the biggest problem. The SLC 500 used Data Highway Plus, which modern systems couldn’t easily connect to. This meant we couldn’t get accurate data on things like how well the equipment was working.

After this phase, we knew what to do first. We decided to move the PLC to a newer PAC system. This would help us collect better data and make the system more reliable and efficient.

Solution Architecture: PLC/PAC migration path, servo kits, safety circuits, HMIs, historian tags

The solution’s architecture is key to updating old equipment. The team replaced the SLC 500 with a B&R Automation PC-based controller. This change made the system more efficient by combining logic, motion, and HMI into one unit.

A temporary IoT gateway helped during the transition. It connected the Data Highway Plus protocol until the system switched to Ethernet/IP. This change improved communication across the plant.

Outdated servo drives and motors were replaced with integrated servo kits. These kits have IP65 drives, saving space and making wiring easier. This upgrade improved efficiency and reliability.

Safety circuits were also updated to use openSAFETY over Ethernet. This upgrade brought networked emergency stops and zone control. It made the workplace safer.

A 15-inch widescreen HMI was programmed with PackML state models. This made machine behavior standardized and improved operator interaction. It allows easy monitoring and quick response to issues.

47 critical historian tags were set up for the plant’s OEE dashboard. These tags track important data like run status and cycle count. They support condition-based maintenance and real-time tracking.

In conclusion, the servo upgrade and solution architecture greatly improved the plant’s operations. For more on modern technology in machinery, visit this resource.

Fabrication and FAT: panel build, software mocks, recipe mapping, change-control docs

The process of making and testing new control systems is key. A UL-certified panel shop built the control enclosure. It had a PAC, servo drives, safety relays, and Ethernet switches.

Before sending the panel, a detailed FAT was done at the integrator’s place. This test used a digital twin of the filler’s I/O and motion axes. It let the software mimic full production sequences. Fault injections were also done to check the system’s strength.

All 12 product recipes were carefully mapped from the old to the new tag structure. Each recipe was checked for important things like:

• Fill volumes
• Cap torque
• Conveyor speeds

Also, change-control documents were made to meet the plant’s GMP needs. These documents tracked every software update, parameter change, and test result. This ensured everything was well-documented.

This thorough validation is vital to make sure the system works right on the plant floor. It also helps with regulatory audits, making things more efficient and compliant.

Cutover Strategy: weekend window, rollback plan, temporary bypasses, permit to work

A well-planned cutover strategy is key to a smooth transition to new systems. The plan was to do the cutover over a 48-hour weekend. This way, it wouldn’t disrupt important production times.

A rollback plan was also set up. The old SLC 500 rack and servo drives were kept ready. They could be quickly switched back if the new system had problems.

For safety, temporary bypasses for the new safety circuits were made and tested well. These steps kept operations safe while the new systems were being added. Also, a permit-to-work system was used. This ensured all electrical and mechanical isolations were checked by the safety officer.

The new safety upgrade brought in networked openSAFETY. It made zone-specific lockout/tagout procedures easier. This meant maintenance could clear the machine faster for routine tasks. This showed how a good cutover plan and modern safety tech can reduce risks and lead to successful commissioning.

Commissioning and Training: IQ/OQ, operator workflows, maintenance routines

Training during commissioning is key to boosting productivity. A detailed plan was followed to check every part of the setup. The Installation Qualification (IQ) made sure all hardware was set up right. The Operational Qualification (OQ) tested if the machine could run at the right speeds for all recipes.

The Human-Machine Interface (HMI) showed real-time OEE data. This helped operators see how they were doing and make changes fast. Training was split into three levels for different people:

• Operators: They learned new PackML workflows for quick changes.
• Maintenance Technicians: They got used to new diagnostic tools and videos on the HMI.
• Engineers: They had deep dives into PAC programming to understand the system well.

The on-machine help system was a big help, guiding operators through common problems. This cut down on relying on old ways of fixing things. It made it easier for everyone to get used to the new tech.

This detailed training plan was critical for the OEE improvement goal. As operators got better at their jobs, they could work faster and have less downtime.

Measured Results: OEE delta, MTBF/MTTR trends, speed curves, scrap reduction, operator survey

The retrofit showed great results over six months. The Overall Equipment Effectiveness (OEE) jumped from 62% to 78%. This boost came from a 14% reduction in downtime and a 9% improvement in performance rate.

Also, the Mean Time Between Failures (MTBF) went up from 47 hours to 128 hours. The Mean Time To Repair (MTTR) fell from 52 minutes to just 18 minutes. These changes were thanks to accurate fault codes and advanced diagnostics.

Speed curves showed the filler running at its 400 bottles per minute rate consistently. This stopped the slowdowns seen before. Scrap was cut by 3.2 percentage points, saving about $87,000 a year in materials.

An anonymous survey of operators showed they were very happy. They gave the new system a 4.6 out of 5 for how easy it was to use. They liked the simple Human-Machine Interface (HMI) and the lack of paper logs.

Financials and Risk: capex vs like-for-like replacement, payback, cyber/lockout improvements

Looking into the financial side of updating old equipment shows big savings and less risk. The cost to update the 1990s filler was $340,000. This is much less than the $1.2 million for a new one with similar features. This means a 72% capital avoidance, showing how updating is cheaper.

The investment paid off in just 11 months. This quick return comes from less waste, lower overtime, and more production. These changes make the operation more efficient and profitable.

Updating also lowered operational risks. The old system was replaced with a modern one for better security. This new system has user checks and encrypted messages, keeping threats away.

Also, the safety system now makes it 60% faster to stop the filler safely. This cuts down on danger from harmful energy, making the workplace safer.

Even though it’s hard to measure, these safety steps are key for the plant’s future. Upgrading not only saves money but also makes operations safer and more efficient.

Lessons Learned and reusable standards

Retrofitting legacy equipment taught us a lot. It’s key to involve operators early on. Their input helped us improve our analysis of possible failures.

Using PackML as a state model made integrating with MES easier. This move helped us track OEE at the line level in the future. A single controller reduced complexity and cut down on spare parts.

We documented every step of the migration process. This included choosing sensors and mapping historian tags. Now, we have a standard for updating other old machines, like a 1998 labeler and a 2001 case packer.

This story shows that old machines can become valuable data sources. A ‘Smart Factory’ doesn’t need new equipment. It’s about making the most of what we already have. By following international standards and focusing on what works, we can work better and spend less.