Wireless Andon and Production-Line Monitoring
1. System overview
The Andon system addresses shop-floor production abnormalities. Audible and visual alarms immediately notify the responsible personnel so they can respond, resolve the problem and restore normal production. It records abnormal-event trigger times, personnel sign-in and response times, and handling times for subsequent problem analysis and performance assessment.
The data-acquisition software uses object-oriented C++ for execution efficiency, portability, extensibility and sustained industrial operation. User software uses Java for a simple interface and cross-platform operation.
2. System architecture
System architecture overview.
3. Functions added to the standard Andon system
Production-plan management
Daily production tasks can be entered in advance. Operators use shop-floor terminals to start, pause and finish a line's planned task. The system follows the plan. Urgent orders can interrupt the current task; once the urgent order is completed, the previous production task resumes.
Production takt time
Shop-floor LED boards display the preset production-cycle time. If work finishes within the cycle, the display starts the next countdown. If it is not finished, the time becomes negative and the overrun is recorded. Countdown warnings can be configured: for example, for a product assembly taking 10 minutes, an Andon voice announcement can remind workers when 3 minutes remain.
Overall equipment effectiveness (OEE)
OEE = availability × performance × quality. It reflects the combined effectiveness of an individual machine, a production line or all production equipment in a factory. Analysis can help identify equipment bottlenecks affecting availability and help operators, production managers and maintenance staff improve equipment productivity and progressively reduce losses that affect OEE.
Real-time production-data acquisition
Barcode scanners, electronic counters, counting buttons, production-equipment I/O ports, photoelectric switches and other acquisition devices collect production data on site. Managers can use these live data to adjust production tasks promptly.
4. Hardware and software configuration
Hardware includes tablet terminals, workstation stack lights, office and shop-floor displays, an industrial server, voice-playback equipment, operator terminals, data collectors, I/O controllers, card-reader modules, data-transmission modules and network-access equipment.
Software modules cover production plans, takt time, OEE calculation, real-time acquisition, Andon calls, workstation stack-light control, display boards, abnormal-event statistics/enquiries/analysis, voice announcements, and SMS/email notifications. The industrial server requires an Internet connection to send SMS messages and email.
System diagrams and screens
