• Juanita Princepio has recorded the costs of an automatic guided vehicle (AGV) that moves materials around an assembly hall.
• The longer the AGV works without maintenance, the higher are the expected failure costs (shown below).
• The maintenance also affects the resale value, giving a varying capital charge.
• Preventive maintenance can be done at a cost of £1000 and this brings the AGV back to new condition.
1. What is the best time between maintenance periods?