CMfgE key terms

How easily a material can be cut by a machining process, judged by tool wear, cutting forces, surface finish, and chip formation. Ratings guide cutting speed and tool material choices for a given workpiece.

Progressive loss of cutting-edge geometry from abrasion, adhesion, diffusion, or chipping during machining. Wear rate limits cutting speed and drives tool-change intervals, cost, and dimensional drift on production parts.

The cutting time a tool lasts before reaching a wear criterion, often expressed by the Taylor equation relating speed and life. It sets economic cutting speeds and tool-change scheduling in machining planning.

The small-scale topography of a machined surface, described by roughness average and related parameters. It depends on feed, tool nose radius, speed, and vibration, and is usually specified as a drawing requirement.

The network of sprue, runners, gates, and risers that delivers molten metal into a mold cavity and feeds shrinkage. Its design controls fill patterns, turbulence, porosity, and yield in casting operations.

A reservoir of molten metal connected to a casting that supplies liquid to compensate for solidification shrinkage. Risers must solidify after the casting section they feed, which drives their size and placement.

Internal voids in a casting or weld caused by trapped gas, shrinkage, or incomplete feeding during solidification. It reduces load-bearing area and fatigue life, and is detected by radiography or ultrasonic inspection.

Excess material forced into the gap between die halves in forging, die casting, or injection molding. It is trimmed afterward and adds cost, so die closing and process force are controlled to limit it.

A slight taper built into the walls of a molded, cast, or forged part so it can be removed from its tooling. Insufficient draft causes scuffing, ejection damage, or the need for side actions.

Elastic recovery of sheet metal after forming loads are removed, causing the part to deviate from the tool shape. It grows with yield strength and bend radius and is compensated by overbending or tool correction.

The precut sheet-metal piece that enters a forming or drawing operation. Blank size and shape determine material utilization and must account for material flow during drawing and trimming allowances.

The region of base metal next to a weld that is metallurgically altered by heat but not melted. It can soften or harden the material and often controls weld joint strength and cracking risk.

The capacity of a metal to be joined by welding into a sound joint with acceptable properties under a given process. It depends on composition, thickness, and preheat or post-weld heat treatment needs.

The standard categories of equipment loss used in total productive maintenance: breakdowns, setup and adjustment, idling and minor stops, reduced speed, process defects, and startup losses. They structure downtime and effectiveness analysis.

A metric combining equipment availability, performance rate, and quality rate into one index of productive time. It highlights where losses occur and is a common target in lean manufacturing improvement programs.

A maintenance strategy in which servicing, inspection, and part replacement are scheduled from time, usage, or condition data rather than waiting for failure. It reduces unplanned downtime and supports predictable capacity.

The available production time divided by customer demand over the same period, giving the pace at which one unit must be completed. It aligns line capacity and staffing with actual demand rather than capacity alone.

The operation with the least capacity in a production chain, which limits total system output. Improving non-bottleneck resources does not raise throughput, so scheduling and buffers are focused there.

A signal-based pull system in which cards or electronic triggers authorize replenishment of material consumed downstream. It caps work-in-process inventory and links production pace to actual consumption.

The longest sequence of dependent activities in a project schedule, which sets the minimum project duration. Delays on the critical path delay completion, so it receives priority in scheduling and resource allocation.

A bar chart displaying scheduled activities against a time axis, with bars showing start, duration, and overlap. It communicates sequencing and progress and can highlight float relative to the critical path.

The process of matching available labor, equipment, and time to forecast or booked demand. It identifies capacity gaps, supports make-or-buy decisions, and sets realistic delivery commitments for manufacturing operations.

Visible layer offsets on the inclined or curved surfaces of an additively manufactured part, caused by finite layer thickness. It is reduced by thinner layers, part orientation, or post-processing and affects surface finish.

The thickness of each deposited or solidified layer in an additive process. Smaller values improve surface detail and reduce stair-stepping but increase build time and part count per build.

The rotation of a part within the additive build volume, which determines support needs, layer cross-sections, anisotropy, and surface quality. Orientation choices trade build time against strength and finish.

Sacrificial material printed beneath overhangs and cantilevers to hold them during an additive build. Supports add material, time, and post-processing labor, so orientation is chosen to minimize them.

Operations after an additive build such as support removal, cleaning, curing, machining, heat treatment, and surface finishing. It often dominates cost and lead time and determines whether parts meet final tolerances.

Direction-dependent material properties, common in additively manufactured parts because layer bonds are weaker than in-layer bonds. It means build orientation affects strength, so test coupons should match production orientation.

An additive process in which a laser or electron beam selectively melts successive layers of spread powder. It produces fine features and good mechanical properties and requires powder handling and support removal.

An additive process that deposits a liquid binder into a powder bed to form each layer, followed by curing and often sintering. It builds quickly without a melt pool but requires debinding and densification steps.

A virtual model of a physical asset or process, kept synchronized with real operating data. It supports simulation, predictive maintenance, and performance optimization without disrupting production equipment.

A network of sensors, machines, and controllers that exchange data over standard protocols. It supplies the real-time process and equipment data that feed analytics, dashboards, and digital twins in a smart factory.

Processing data near the machines that generate it rather than in a distant data center. It cuts latency for control decisions and reduces network load, which matters for fast closed-loop manufacturing applications.

Using sensor trends and models to forecast equipment failure and schedule intervention before breakdown. It reduces unplanned downtime compared with reactive repair while avoiding unnecessary scheduled servicing.

Monitoring a process with control charts to distinguish normal variation from assignable causes. It supports decisions to adjust or leave a process alone and helps maintain capability over production runs.

A measure of how well a stable process meets specification limits, expressed as indices such as Cp and Cpk. It separates process spread from centering and guides tolerance and improvement decisions.

A structured study of how much variation comes from the gauges and operators used to measure a product. It quantifies repeatability and reproducibility before process data are trusted for capability or control decisions.

An engineered system in which physical equipment and networked computation monitor and control each other in real time. In manufacturing it links machines, sensors, and software for adaptive, connected production operations.