Implementing an AGV System

Operation

Operation is the useful lifetime of the system following the launch of operation. It encompasses the day to day usage, changes, and problems in the system during its active term.

Equipment Doesn’t Make Systems Work, People Make Systems Work

During the operational stage, the system depends more on people’s attitude than anything else. The system is there to help people do their jobs. It will succeed only if people accept and support it.

On the supervisory level, people must be wholly committed to the system’s operation. They must respond immediately to any system need such as operator misuse, breakdown, shifting production requirements or improved operational methods. The system must be a priority, a daily supervisory activity.

User level interaction with the system must remain positive at all times. If the system fails to serve the user, it has not been effectively used. Providing the user with a means of offering feedback on the system operation is vital to retaining user support. Using monthly internal system operational audits and user input allows for system dissatisfaction to be voiced and rectified. Often the input is positive suggestions for improving the system operation. A specific program for user input, either via suggestion submittal, meetings, or informal canvas, is extremely helpful in maintaining an acceptable level of system operation.

The word "automatic" in AGVS does not mean maintenance free. Automatic implies without operator intervention for the prescribed operation. Maintenance of an AGVS is a critical element from day one of operation. Successful systems are not those which require no maintenance, but those which have the best maintenance support.

Establishing an effective AGVS system maintenance program involves several elements. First, maintenance should be closely followed and monitored. Preventative maintenance is a must and the programs are established for this. Accurate records of repairs help pinpoint potential design problems and allows the vendor to rectify repetitive problems. Second, retraining is necessary at least once a year. The vendor can provide this at your site or at his/her factory. Retraining allows new maintenance personnel to receive factory guidance and refreshes maintenance and troubleshooting procedures for existing personnel. Along with this is maintaining accurate documentation on the system. Establish a formal process for system drawing updates. Do not let manuals become misplaced.

Spare parts are often overlooked critical elements in the system operation. Often users have not even budgeted for a spare parts supply. During the first few months of operation, this is critical even though the system is under warranty. Warranty programs will replace or repair defective parts. However, can you afford to be without a piece of equipment, or even the system, while a part is being shipped to/from the factory? Usually a level of spare parts equal to 3-5% of the initial system contract is adequate in most systems.

It’s Not Over, ‘til It’s Over

Keeping regular tabs on the AGVS system is the best way to ensure performance objectives are met. This function should only end when the system is terminated, as in most cases, after many years of operation.

AGVS systems tend to take on a life of their own. The users bend, twist, and shape the system to better fit their use. The inherent flexibility of the system promotes future system enhancement and modification. However, not all change is good. Many changes can go unnoticed and have a detrimental effect on the overall system performance.

There are methods available for monitoring a system’s hourly, weekly, and monthly performance. CRT monitors are now commonly used to allow supervisors to check the AGVS system’s real-time condition. Where are the vehicles? Where are they going? Where are traffic bottlenecks? Having a real-time monitor in the system allows for almost instantaneous reaction to system anomalies. It speeds recovery in a failure by pinpointing the area and type of failure. By accumulating this information in the AGVS System Performance Reporter, information can be summarized and performance reports printed out for a given period of time. The reports describe how many loads were moved between stop stations, how much work each vehicle performed, and how much idle or traffic congestion time occurred. Analysis helps determine if overall system performance is as expected or below normal in an area.

The AGVS System Analyzer is a new tool that accumulates detailed equipment performance data. While the system performance reporter helps determine how well the overall system is operating, the system analyzer is extremely useful in determining how the individual elements in the system are performing.

Areas such as traffic control efficiency, path throughput rate capacity, vehicle error logging, and other factors related to equipment or system design can be carefully investigated on a periodic basis. An instant playback feature is also available. This allows the user to replay the exact system performance on a CRT screen from any recorded period of time.

This is an invaluable, investigative tool. For example, someone on the third shift reports an AGV load transfer malfunction. They state that an AGV collision has taken place, but can’t determine how it happened or which vehicles were involved. The system analyzer "replay feature" can then go back and show the vehicle movements at the time in question. This allows the situation to be recreated and the correct vehicles identified.

Periodic system audits performed by your AGVS vendor can be used to keep your system operating at peak efficiency. These audits provide a means of fine tuning the system operation as user requirements change. If for example, six months from now your system develops different material flow patterns, the system design should change to remain efficient. This change can be spotted in a periodic audit and necessary traffic control and path changes implemented.

You should never consider the project over. For the system to remain a highly productive part of the plant, periodic review of all facets — user interface, maintenance, flow, etc., needs to be performed.