Production Control and Continuous Improvement

Availability takes into account Down Time Loss and any event that stops planned production (equipment failures, material shortages and changeover time)
Availability = Operating Time / Planned production time

Performance takes into account Speed Loss (includes factors that cause the process to run at less than maximum possible speed) Examples include machine wear, substandard materials, mis-feeds, and operator inefficiency.
Performance = (Total Pieces / Operating Time) / Ideal Run Rate

Quality takes into account Quality Loss (production pieces that do not meet quality standards, and pieces that require rework)
Quality = Good Pieces / Total Pieces