Manufacturer-suggested maintenance intervals are good starting points, but they aren't based on your constraints and resources. Unless you're in an ideal situation, you have to decide what to maintain, how much maintenance to perform, and how often.
If uptime is your primary goal, then you could make these choices based on the risk of downtime. Probability Risk Assessment (PRA) is a tool for doing that. An excellent resource for understanding and applying PRA is the IEEE Gold Book, Standard 493, Recommended Practice for Design of Reliable Industrial and Commercial Power Systems.
The Gold Book explains PRA assessment and provides failure rates and repair times. However, Gold Book failure rates and repair times are unlikely to be the same as those at your facility, because Gold Book numbers are based on national data rather than on your data. Tip: Collect the same kind of data from your facility.
With PRA, you factor in several key variables to predict downtime, availability, and failures per year. As you may have guessed, this is calculation-intensive. Don't despair; PRA analysis software is available.
If you have more maintenance than resources to accomplish it, PRA may be your best solution for properly prioritizing work and allocating resources.