Machinery and equipment are the most valuable asset of the manufacturing-manufacturing enterprise. But having good machinery and equipment is not enough but also good maintenance. Conversely, poor maintenance will result in several dozen types of damage due to downtime (increased operating costs, raw materials and energy, increased risk of unsafety and environmental harm, reduce machine life, equipment, reduce productivity and quality, reduce customer satisfaction and trust, reduce sales and profits, etc.) are sunken costs that we do not usually see or do yet. Seeing that we only care about the floating cost is the cost of buying spare parts and repairing costs. The picture below is the iceberg maintenance costs.