Quality and Manufacturing Systems: definition of process capability for a machine tool In industrial engineering, the process capability of a machine is defined as the machine’s inherent ability to consistently achieve which of the following outcomes over time?

Introduction / Context:
Process capability is a cornerstone concept in quality engineering and manufacturing systems. It expresses how well a machine–process combination can repeatedly meet dimensional tolerances and surface finish requirements without continual adjustment. Unlike mere output rate, capability is about precision, repeatability, and conformance to specification.

Given Data / Assumptions:

• A stable machine and process under statistical control.
• Specification limits exist for size, geometry, and surface finish.
• Normal process variation is present due to machine, tool, and material.

Concept / Approach:
Process capability concerns the natural spread of the process versus the allowable tolerance band. In practice, capability indices like Cp and Cpk summarize whether the machine and its process can hold tolerance consistently. Surface finish is also a capability attribute, tied to machine dynamics, tool condition, and cutting parameters.

Step-by-Step Solution:
Identify what “capability” measures: repeatable conformance to tolerance and finish.Recognize what it does not measure: the count of operations, speed range, or theoretical maximum throughput.Match to the option that reflects precision and conformance → maintaining a definite spectrum of tolerance and surface finish.

Verification / Alternative check:
Shifting throughput (units/min) does not imply capability if dimensions wander. Similarly, running many operations does not guarantee that any critical characteristic falls within spec. Capability indices directly tie to tolerance and centering.

Why Other Options Are Wrong:
Option (A) describes productivity, not capability. Option (B) is about routing/complexity, not precision. Option (C) concerns machine features (speed steps). Option (E) promises zero defects irrespective of variation, which is unrealistic and not the definition.

Common Pitfalls:
Confusing capability with capacity; ignoring process centering; assuming speed increases automatically improve capability.

Final Answer:
hold a definite spectrum of tolerance and surface finish