Each key product feature is studied at Caroba in order to match the best measurement method with the critical to quality (CTQ) feature’s characteristics and specifications. An ANOVA study is employed with either a crossed or nested method that is dependent upon the destructive nature of the measurement method. The number of samples, inspectors and trials in the study are chosen to match customer requirements. Ideally, samples are chosen from a designed experiment so the feature variation will adequately challenge the measurement method and resulting distinct category designations for the method will be reliable.

The study variation is reported as a percentage of the product feature’s tolerance. This percentage will be less than the customer’s acceptance criteria. Caroba’s Engineering and Quality Departments strive to provide each customer with product data that is reliable and meaningful.

Caroba uses designed experiments to optimally set processes for customer’s products. A product’s key features are considered when choosing the key process factors for a product. These factors are then typically varied according to a two level full factorial design in a controlled experiment. The key features of the experimental samples are measured using approved methods and the factor variation can then be mathematically related to product variation. This information is used to obtain optimal process settings for the product’s specifications.

High / Low studies based around optimal process settings are also used to verify that products will meet their specifications.

Caroba’s Engineering and Quality Departments are dedicated to working with customers to ensure the ideal tooling and process combination for a product.

Caroba performs process capability analysis during product implementation to establish status and areas for improvement. Caroba also performs process performance analysis during production to monitor status. Capability or performance indices (Cpk or Ppk) are calculated for comparison with customer criteria. Control charts are developed for each key product feature and used on a real-time basis during production. By establishing and monitoring this information, Caroba is able to comply with a variety of its customers’ programs including the cert-to-stock requirements of six sigma customers. The following are examples that illustrate Caroba’s ability to manufacture product that will consistently meet specification.

Cpk and Ppk values exceed the industry standard minimum of 1.33 on a consistent basis. Caroba’s Engineering Department has a thorough understanding of Quality Engineering techniques and injection molding variation. This knowledge is applied to meet the six sigma requirement for minimum Cpk and Ppk values of 2.0.

Caroba is pleased to offer services to help customers comply with their corporate standards and regulatory requirements. Caroba has experience with tooling and process analyses and can perform studies and provide various data and reports upon request. Services of Caroba’s Engineering and Quality Departments can be customized to meet each customer’s requirements.