Defining and Clarifying Reliability in Manufacturing Operations

Reliability is a cornerstone of operational excellence. Plant leaders frequently cite it in mission statements—“increase profitability through greater reliability.” Yet when asked to define and quantify the term, answers are often vague.

In manufacturing and process industries, the precise definition of reliability is still emerging. Service sectors have not yet codified the concept either. Consultants introduce the language to sell new frameworks, but the underlying meaning remains unclear.

The ultimate goal for any plant is to maximize production reliability: the highest possible output with existing resources, achieved by eliminating waste in both equipment and process reliability. Together, these form the basis of reliable production.

This performance can be captured by Overall Production Reliability (OPR). Traditionally called Overall Equipment Effectiveness (OEE), OPR is preferable because it encompasses all production‑related waste—not just equipment‑related losses. The formula is:

OPR = Quality (%) × Speed (%) × Time Availability (%)

The three factors—Quality, Speed, and Time Availability—account for every loss on a production line. OPR is therefore an ideal metric for aligning objectives across operations, maintenance, and engineering teams.

Operations focus on process reliability: keeping the manufacturing process free from waste caused by sub‑optimal parameters—pressure settings, machine speeds, cutting‑tool selection, or chemical concentrations.

Maintenance prioritizes equipment reliability. Failures, component wear, or breakdowns generate waste, degrade quality, and slow throughput. A robust maintenance strategy is essential to sustain OPR.

Engineering’s role is to support both equipment and process reliability through Life‑Cycle Cost (LCC) design. LCC evaluates the total cost of ownership—from purchase to retirement. Unfortunately, engineering departments often concentrate only on schedule and budget, overlooking reliability and maintainability features such as jacking bolts for motor and gearbox alignment.

World‑class shaft alignment is nearly impossible without proper jacking bolts. Specifying them in the design phase ensures reliable operation from day one.

In short, companies must clarify what they mean by “reliability.” Clear definitions help employees understand and pursue production reliability goals. In the next column, we’ll explore how maintenance management can set actionable targets by defining “equipment reliability” for their teams.