Service Design & Transition Manager

About the Role

In this role you will lead service design activities, defining project and business roles, reviewing requirements, scoping support, developing total cost of ownership models, establishing SLAs, and producing a comprehensive Service Design Package that addresses capacity, availability, monitoring, resources and costs throughout the service lifecycle. You will also manage service transition, governing end‑to‑end processes, coordinating handovers from project delivery to operational support, advising project managers, handling RAID items, ensuring testing is approved, chairing Service Acceptance Boards, supporting early‑life support and overseeing post‑go‑live actions. • Define project and business roles throughout the lifecycle. • Review and validate service requirements with relevant teams. • Scope high‑level support and determine resource and skill profiles. • Develop service total cost of ownership and required monitoring tools. • Establish Service Level Agreements aligned with business and support capabilities. • Create and maintain a Service Design Package covering capacity, availability, monitoring, resources and costs. • Ensure service designs meet business objectives, operational needs and user expectations. • Align service architecture with existing Digital IT landscapes. • Identify and remediate gaps in processes, systems or resources. • Participate in design reviews to confirm service readiness. • Govern end‑to‑end Service Transition, ensuring compliance with templates and governance. • Facilitate seamless handover from project delivery to operational support. • Advise Project Managers on Service Transition best practices. • Act as primary liaison between Project Managers and stakeholders. • Manage and mitigate risks, issues, assumptions and dependencies (RAID) for service delivery. • Verify testing against business requirements is completed and approved. • Coordinate Internal Service Acceptance Boards and track post‑go‑live actions. • Support Early Life Support and oversee Acceptance into Service processes.

Key Responsibilities

• ▸service design
• ▸cost modeling
• ▸sla management
• ▸architecture alignment
• ▸transition governance
• ▸testing verification

What You Bring

Southern Water is undergoing a major digital transformation and is looking for skilled, collaborative people to help deliver its initiative. The Service Design and Transition Manager will ensure new or changed services are designed effectively and transition smoothly into operational environments, aligning with the company’s governance frameworks. The successful candidate is a self‑starter with strong ITIL knowledge (Service Design, Transition and Operations), proven experience delivering service design and transition within IT projects, and the ability to develop support models, SLAs, OLAs and workflow processes. Excellent stakeholder management, communication, problem‑solving, and organisational skills are essential, together with familiarity with project governance and operational readiness assessments. ITIL Foundation V3/V4 certification and knowledge of IT project management methodologies are required. • Demonstrate self‑starting attitude with minimal supervision. • Strong understanding of ITIL Service Design, Transition and Operations. • Proven experience delivering service design and transition in IT projects. • Expertise in developing Service Support Models, SLAs, OLAs and workflow processes. • Excellent stakeholder management, communication and facilitation skills. • Ability to conduct operational readiness assessments and service assurance activities. • Hold ITIL Foundation V3/V4 certification and knowledge of IT project management methodologies.

Requirements

• ▸itil foundation
• ▸service design
• ▸service transition
• ▸slas
• ▸stakeholder management
• ▸project management

Benefits

The role closes on 17/02/2026 and is based in Durrington (Worthing) with a hybrid arrangement of two days per week in the office. It is a permanent full‑time position offering a salary up to £60,400 per annum (depending on experience) plus bonus, and a standard 37‑hour week. Southern Water is investing £7.8 bn between 2025‑2030 to enhance resilience, sustainability and service excellence, offering a unique opportunity to influence strategic decisions and drive long‑term value. The company embraces diversity, welcomes applicants from all backgrounds, and will provide reasonable adjustments during recruitment if needed. Employees benefit from a culture that values impact, personal growth and innovation, with 24/7 incident support expectations and opportunities to join a supportive incident support team. Flexible working is considered where possible, and the organisation encourages candidates to apply even if they do not meet every requirement.

Work Environment

Hybrid