Equipment is the most manageable area to improve ROI. The main expense for equipment is maintenance. Daily checks of fluids, grease requirements, and overall potential problems is important. Check sheets of things to observe and/or do are important for operators before they start their shift.
Forklifts can be gluts on maintenance if not properly monitored. Hydraulics, moving parts, filters, and even engine compartments can be a problem if not checked regularly. I have seen forklifts handling scrap paper bales burst into flames because of scrap buildup in the engine compartment.
Age of equipment is important. In many cases, even though a new machine has a high upfront cost the warranty and initial maintenance can be much less than constant repairs on older equipment. I have found, depending on the equipment, that buying new and trading in before value is lost is more economical than trying to nurse older equipment.
Cross-training, computerized inventory control, and overlapping shifts (as opposed to overtime) can also be used to improve ROI.