Xerox Electronic Assembly
The Scenario
Xerox were planning a major investment in an assembly area for a new breed of printer. The assembly line would use automatically guided vehicles (AGVs) to deliver three product types around a large assembly area. Around £2m was to be spent on AGVs alone.
The Challenge
The level of interference and vehicle delays from the AGVs meeting people & forklifts on their circuit would determine the circuit time around the assembly area. More delays mean that more AGVs would be needed to obtain the required throughput.
Xerox needed to ascertain two things:
- How could the use of AGVs best be optimised for minimum interference and hence maximum throughput?
- How many AGVs would be needed?
Initial spreadsheet analysis indicated that 36 AGVs would be required, but this was a static analysis that could not model the dynamic nature of the situation or “randomly” occurring events. Neither could it provide any insight into how best to operate the assembly area to maximise AGV efficiency and hence product throughput.
The Solution
Xerox’s Business Improvement Manager commissioned Paragon Simulation to provide an animated model of the assembly circuit for Xerox to operate.
The model replicated the patterns of AGVs moving around the circuit and the congestion resulting from interference between AGVs and manually operated equipment such as fork lift trucks, people and other processes. The model was designed for Xerox to use to experiment with different levels of interference and to determine the number of AGVs needed to obtain required throughput. Complex dynamics that would create production losses were accurately predicted.
The model was built and delivered to Xerox completely ready-to-use – which proved vital, considering what then transpired.
The Benefits
On the day of model delivery, Xerox’s project timescales were pulled forward by two weeks and a decision about the number of AGVs to be ordered was needed by end of that day. The day had been scheduled for training, but instead the model was immediately pressed into action. Fortunately, the ease of use of the Paragon Information Manager (the model interface) made this feasible.
An investigation using the model was carried out, and this revealed that only 33 AGVs would be needed, 3 fewer than the original spreadsheet analysis had indicated would be required at the expected level of interference.
The saving of 3 AGVs at £60k each saved Xerox £180k – in an afternoon! The model cost around 13-days to build & deliver.
Having been pressed into immediate action, the model was then available for Xerox to further optimise the operation of AGVs and to model in advance the impact of any future changes such as altering the product mix or assembly procedures.
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