PlaxidityX TARA and Cyber Security Architecture Design Services is a professional services offering targeting automotive OEMs and Tier 1 suppliers. It provides structured cybersecurity consulting across the vehicle development lifecycle, with a methodology compliant with ISO 21434 and ASPICE standards. The service is organized into three primary areas: **TARA and Security Concept** Performs threat analysis and risk identification, categorization, and assessment for vehicle architectures, systems, and components. Following the TARA, a security concept and goals are defined, including suggested mitigations and countermeasures. **Security Requirements** Once the TARA and security concept are complete, PlaxidityX drafts and defines cybersecurity requirements documented in a Security Requirements Specification, which is used to develop security mechanisms for all vehicle components and systems. **Architecture Review** Conducts a pre-audit assessment of the planned vehicle's E/E architecture and connected services infrastructure to identify remaining security gaps and suggest remediation steps, supporting preparation for type approval. Additional service models include staff outsourcing (cybersecurity engineers join the client organization on a project basis), customer-defined scope engagements, and a Cyber Security Department as a Service model where PlaxidityX acts as the client's full cybersecurity division across the product development lifecycle. The service uses a multi-level TARA approach covering vehicle, component, system, and software levels, and has been applied across dozens of engagements for Tier 1 suppliers and OEMs.