| Product Definition | Confirm roller type, track profile, mounting method, outer diameter, width, bore or stud size, and required quantity. | Provide a dimensioned drawing, sample part, or application photographs before quotation. | 2D drawing, 3D CAD file, product specification sheet, revision-controlled quotation. | Incorrect fit, incompatible track geometry, and avoidable redesign. |
| Load and Motion | Specify radial load, axial load, speed, acceleration, duty cycle, travel length, shock loading, and expected service life. | Compare the application load with the supplier's published static and dynamic ratings; request calculation assumptions. | Load-rating table, life calculation, operating-condition checklist. | Premature wear, brinelling, excessive vibration, and roller failure. |
| Material Selection | Hardened bearing steel Stainless steel Engineering polymer | Match material and hardness to corrosion exposure, temperature, contamination, and required rolling life. | Material certificate, hardness report, corrosion-resistance statement where applicable. | Corrosion, deformation, surface damage, and unsuitable temperature performance. |
| Surface Treatment | Possible treatments include zinc plating, black oxide, passivation, nitriding, or other specified coatings; treatment must match the operating environment. | Check coating type, thickness range, masking requirements, and dimensional allowance after treatment. | Coating specification, thickness record, salt-spray report when contractually required. | Rust, dimensional interference, coating peeling, and inconsistent appearance. |
| Dimensional Accuracy | Control critical dimensions such as roller diameter, bore, width, concentricity, runout, and track contact profile according to the approved drawing. | Define tolerances before production and require measurement of critical-to-function characteristics. | Inspection standard, dimensional report, calibrated-equipment records. | Excessive play, binding, uneven load distribution, and poor positioning accuracy. |
| Bearing and Lubrication | Confirm bearing arrangement, seal type, grease specification, relubrication requirement, and allowable operating temperature. | Review the lubrication method and verify whether the product is supplied pre-greased or dry. | Bearing specification, lubricant data sheet, maintenance instructions. | Noise, heat generation, contamination ingress, and shortened operating life. |
| Sample Approval | Use production-intent samples to validate fit, travel smoothness, noise, load behavior, and installation procedure. | Test samples under representative load, speed, travel, and environmental conditions. | Sample approval record, test photographs or videos, signed drawing approval. | Mass-production deviations and application-level incompatibility. |
| Pre-Production Inspection | Review raw materials, production schedule, approved drawings, tooling, process controls, and packaging requirements before bulk manufacturing. | Conduct a remote document review or arrange an independent factory inspection. | Pre-production inspection checklist, approved bill of materials, production plan. | Unapproved substitutions, schedule misunderstandings, and process instability. |
| During-Production Inspection | Inspect semi-finished parts, heat treatment, machining, assembly, surface finish, and process capability at defined checkpoints. | Use sampling plans based on order quantity and product criticality; record nonconformities and corrective actions. | In-process inspection report, heat-treatment record, corrective-action report. | Late discovery of defects and costly rework after assembly. |
| Final Inspection | Verify quantity, dimensions, appearance, rotation or sliding performance, marking, accessories, and packaging before shipment. | Apply the approved acceptance criteria and review photos of cartons, labels, and pallet condition. | Final inspection report, packing list, certificate of conformity, shipment release record. | Short shipment, mixed specifications, cosmetic defects, and transit damage. |
| Quality Sampling | Use an agreed sampling method such as ANSI/ASQ Z1.4 or ISO 2859-1 when a statistical inspection plan is appropriate. | Define inspection level, acceptable quality limit, critical defects, major defects, and minor defects in the purchase contract. | Sampling plan, defect classification sheet, inspection measurements. | Disputes over acceptance standards and inconsistent quality decisions. |
| Packaging | Protect precision surfaces from impact, moisture, dust, and metal-to-metal contact; separate parts when scratching is possible. | Approve inner packaging, carton strength, moisture protection, palletization, and carton identification. | Packaging specification, carton marking layout, packing photographs. | Rust, dents, scratching, lost accessories, and handling damage. |
| Shipping Planning | Courier: samples Air freight: urgent cargo Sea freight: commercial volume | Compare total landed cost, transit time, cargo dimensions, customs requirements, and delivery terms. | Commercial invoice, packing list, bill of lading or air waybill, certificate of origin when required. | Unexpected freight cost, customs delay, document mismatch, and delivery uncertainty. |
| Trade Terms | Agree on Incoterms® 2020 responsibilities, named place, export clearance, insurance responsibility, and transfer of risk. | Ensure the quotation, purchase order, and shipping documents use the same trade term and named location. | Sales contract, purchase order, Incoterms statement, freight quotation. | Ambiguous responsibility for freight, insurance, duties, or loss in transit. |
| Lead-Time Control | Separate sample lead time, tooling lead time, production lead time, inspection time, and transit time in the purchasing schedule. | Use milestone dates and obtain written approval for any change affecting the delivery commitment. | Order schedule, milestone tracker, delay-notification procedure. | Production bottlenecks, missed installation dates, and unmanaged schedule changes. |
| Supplier Support | Define response time, engineering communication, spare-part availability, replacement policy, warranty scope, and technical escalation route. | Evaluate the supplier's ability to provide drawings, troubleshooting guidance, replacement parts, and corrective-action reports in English. | Technical support procedure, warranty terms, spare-parts list, complaint form. | Slow issue resolution, unclear warranty handling, and extended equipment downtime. |
| Total Cost of Ownership | Assess unit price together with tooling, inspection, packaging, freight, duties, installation, maintenance, replacement, and downtime costs. | Compare at least two landed-cost scenarios using the same specification and delivery term. | Landed-cost worksheet, quotation comparison, maintenance-cost estimate. | Selection based only on purchase price and higher long-term operating cost. |
