This can vary widely of course with REIT cement bricks you are producing and what levels of automation of brick machinery you have chosen in your operation. My general rule is for every 40 hours run time you need to have 8 hours preventative maintenance time. That means during each day you still have to do the daily tightening of bolts, greasing, check oils and cleaning of machinery.
At the end of the week, normally on a Saturday you would have two people come into the plant for four hours (half day) to checks details that are not part of the daily checklist.
The two maintenance people would be doing the weekly & monthly checklists on all the equipment. This would include examining every inch of the concrete block machinery and doing detailed inspections. By doing these weekly procedures, it will greatly reduce your risk of any downtime during the weekly production runs.
Preventative maintenance will make you money. You need to fix the problems correctly and not just put a Band-Aid or quick fix on the problem. The time will come when all those small quick fixes will cause you to lose a lot of money and you will not be able to grow your business. Remember you have to have good procedures and people to make a concrete products plant successful!