In the first blog on streamlining manufacturing, we discussed how OEE (Overall Equipment Efficiency) and MOM (Manufacturing Operations Management) can improve manufacturing processes. The problem is that many factories are limited in this area because they have older legacy equipment. This older equipment includes manually operated machinery or outdated PLCs, and stand-alone machine tools. None of this equipment was designed to work in a networked, Internet-based environment. Therefore collecting and using data about the operations of these machines has seemed difficult, requiring expensive upgrades. However, new technologies now enable what was once assumed to be challenging to be far easier and less costly.
The problem of legacy plant equipment
Legacy equipment is part of the manufacturing world. Equipment is purchased on the assumption that it will last years and can be depreciated over its useful life. Except for state-of-the-art manufacturing plants built in the past five years, most facilities have industrial equipment that is 20 to 25 years old, or even older. Upgrading to newer equipment to enable smarter manufacturing can cost millions and involves many months of planning, not to mention other investments in process improvement and training.
With this in mind, manufacturers face the challenge of how to transform their factory floor operations so they can get better information on performance, quality levels, and maintenance requirements by using an instrumentation approach that is cost-effective. If they can do this, then manufacturing processes can be integrated with the company ERP system and metrics like OEE (Overall Equipment Efficiency) can be used to monitor overall manufacturing productivity.
How to instrument older plant equipment for MOM
There are a few ways to instrument older plant equipment.
- Flexible, low-cost sensors can be deployed in industrial scenarios. These offer a method for gathering data from a single process.
- Retrofit kits can be quickly attached to older machinery and connected via wired or wireless networks, allowing for better monitoring and allowing modern manufacturing applications like MOM (Manufacturing Operations Management) to collect and analyze the data and integrate it with an ERP system.
- Consumer-grade open-source devices with easy-to-use hardware and software. These devices can read an input, such as a light coming on, and turn it into an output, such as activating a motor and publishing the information online.
These new and cheap technologies can provide the critical real-time manufacturing data that assists with monitoring and scheduling.
Implementing low-cost equipment sensors
After deciding on which type of sensor to use and how to attach them, the second issue is how to ensure the sensor’s data reaches its destination.
Using Wi-Fi technology offers good bandwidth for transmitting data but comes with the cost of a relatively short range, especially in a manufacturing environment with metal or walls that can reduce a signal. Adding repeaters just makes the installation more complex and costly.
Getting sensor data by wiring each sensor is the alternative. This is open-source, intelligent devices are beneficial as they can act as a central data collection point for dozens of sensors and publish the data via the Internet to a web URL.
In the first blog, it was pointed out that any project to optimize manufacturing operations should start with a value stream mapping (VSM) exercise. The same approach should apply when implementing an equipment instrumentation project to highlight problems in the manufacturing process and show where improvements may have the biggest benefit. From VSM, specific machine problem areas can be determined. The results can then be used to ensure that instrumenting a specific piece of equipment is supported by business goals.