On the left side of the table, LGS projects the steps for assembling a fuel injector. LGS also highlights which bins to pick parts, while an overhead vision system confirms the assembler reached for the correct bins. On the right, along the edge of the table, LGS projects the cycle time for performing all the assembly steps.
At minimum, the OPS Solutionâs Light Guide System for showing step-by-step work instructions involves a projector, proprietary software, and a personal computer. To confirm that instruction steps were done correctly, the system needs feedback from devices, such as a machine vision, torque tools, and scanners. Light Guide can run as a standalone system or be triggered by industrial controllers or an MES.
LGS is guiding an operator through the final assembly and inspection of a fully assembled bumper, including verifying that the right parts, such as bolts and plastic clips, are in the right locations.
âLight, Guide and Goâ is an apt advertising slogan for selling Light Guide System (LGS) from OPS Solutions (ops-solutions.com). The slogan could have just as easily been âShow Me the Way,â if not for two Billboard Hot 100 hits of the same title.
Light Guide literally does all of that. âWe project a âdigital canvasâ right onto almost any kind of a product and almost any kind of process,â says Paul Ryznar, founder, president, and CEO, explaining that the projected images âreplace hard-copy work instructions with a highly visual and intuitive workflow,â which is especially helpful in assembly, picking and kitting, inspection, and training. The result, continues Ryznar, is âhigher quality, productivity, throughput, and training effectivenessâthe key drivers of operational improvements and bottom-line results.â
Showing the Way
Light Guide is an âaugmented reality tool.â It combines image projectors, machine vision and other data acquisi-tion technologies, and software to display an interactive, sequential, step-by-step visual guide onto just about any work surface, whether work area, fixture, or part. The projected visuals include color-coded text, images, animations, videos, even blueprints.
The projected image size (âoperating canvasâ) ranges from pixels (e.g., for microscope-guided circuit board assembly) to 20 x 15 ft. from a single projector (e.g., for building a complete tractor or picking/sequencing parts within a warehouse). One LGS personal computer can operate up to six projectors to create a âcanvasâ as large as 180-ft2.
In addition to projecting instructions, Light Guide also confirms that each instruction has been completed correctlyâstep by step. It does this through any number of data collection devices, including machine vision systems, weigh scales, torque tools, USB foot pedals, materials handling systems, barcode readers, and industrial controllers. With these devices, LGS can confirm, for example, that an operator is reaching for the right bin (machine vision), picking up the correct part (weigh scale), and tightening a bolt correctly (torque wrench). Likewise, an overhead vision system enables Light Guide to detect an error in laying out a wiring harness. LGS indicates defects with flashing red visuals; green lights, obviously, indicate a task was done correctly. Given the proverbial âgreen light,â Light Guide then shows the next step in the instruction sequence. This all happens in real time. âBy confirming each task thatâs correctly completed, LGS error-proofs manual operations,â says Ryznar. âItâs the perfect poka-yoke control to reduce defects, rework, and redundant inspections and testing.â
LGS can also be controlled by industrial controllers, inspection systems, manufacturing execution systems (MES), and other automation. For example, in automotive production lines involving multiple product variations, the MES can output specific visual work instructions to workstations on the line. LGS will then guide operators through the appropriate variant assembly steps.
Throughout, LGS can display the predicted (or standard) times for each instruction step and the total cycle time for each build cycle. Optionally, LGS can also record a variety of data, including cycle times (individual steps and by person), date/time stamps, bar codes (individual parts and part runs), and identification numbers (operator and workstation IDs).
This real-time process data and full traceability can be the basis for process analytics leading to operator retraining and process improvements. When used for training, this data can become the basis for determining when training is complete; namely when an operator has reached a targeted level of performance.
Driving LGS is proprietary software from OPS Solutions. Creating a script for LGS has the same look-and-feel as, say, creating Microsoft PowerPoint presentations, according to Ryznar. Using a ribbon interface with icons along the top, people can set up work instructions, the visuals to project (e.g., CAD drawings and videos from a smartphone), data to collect, task completion definitions, alert triggers, displays, and so on. This programming is typically done by the manufacturing engineer or controls engineer; that is, the people typically responsible for the area where LGS is installed, typically responsible for hard-copy or electronic work instructions, and ultimately responsible for product quality and operational productivity.
Light Guide in Action
Light Guide can be used âfor virtually any type of manual process that requires precision and consistency,â says Ryznar. In assembly, displaying step-by-step work instructions directly on a part or assembly process at the right time eliminates âflipping through paper instructions or checking a monitor.â
At manual inspection stations, projections of a visual workflow essentially standardize the inspection processâand the time to do that inspectionâby guiding every inspector through every stepâand confirming each step has been properly completed. Plus the images LGS displays are bright enough so inspectors can see defects much better than with typical workstation/factory lighting.
As a standalone, off-line training system, LGS shows operators the key manualÂ requirements of their job before actually starting that job. Such self-training can significantly reduce overall training costs and establish task-completion benchmarks. âLGS eliminates the trainer-to-trainer variation found whenever you have multiple trainers conducting the same training process,â explains Ryznar. âAnd using LGS for training instead of your existing trainers, people who are typically some of your most experienced and productive operators, frees them up for higher value-added work.â
Projecting work instructions really works. In August 2014, OPS Solutions and Chrysler World Class Manufacturing Academy (WCMA) compared the effectiveness of standard work instructions and LGS visual workflow for two work processes. In assembly, errors were reduced 80%, cycle time was reduced 38%, and throughput was increased more than 80%. In part kitting/sequencing (representing logistics), errors were reduced nearly 90%, cycle time was nearly halved, and throughput was increased by 95%. For most companies, says Ryznar, the payback for LGS is typically in weeks or months, rather than years.Â