5. Interrelationship Special Requirements, Critical Items, & Key Characteristics Key Characteristics Attribute or feature whose variation has a significant effect on form, fit, function, performance, service life, producibility Key characteristics can be critical items or features of critical items. Key characteristics require specific actions for controlling variation Examples: Material chemistry Container/chamber wall thickness Meeting milestone dates. Critical Items Items (functions, parts, software, characteristics, processes) having a significant effect on product realization and use Identified from Special requirements or from 7.3.3 Design Output. Can be independent of Special Requirements. Require specific actions to ensure they are adequately managed. Examples: Material weight properties Protective container/chamber design Overhaul procedures and systems. Special Requirements Requirements at the limit of the industry’s or organizations capabilities Identified by the customer or determined by the organization as having a high risk to being achieved. Typically an output or identified at 7.2.1 or 7.2.2 (Determine & Review Product Requirements). Examples: Weigh less then 16 oz. Operate at -1000 meters under water Require AS9100 Rev C Certification.