Senior Business Manager

Job Description

Today, Assystem is among the top three independent nuclear engineering firms worldwide. With over 60 years of experience in highly regulated sectors, the group supports public and industrial stakeholders in the execution of complex and strategic infrastructure projects, subject to high safety and security requirements.

Assystem mobilizes 8,000 experts in 13 countries and intervenes across the entire project lifecycle, in engineering, project management and digital solutions.

We are seeking an experienced Senior Business Manager to lead a high-performing engineering consultancy portfolio delivering work packages and project-based Engineering outcomes.

This role is accountable for a project-driven P&L, where success is built on the consistent delivery of high-quality engineering outputs, strong commercial control, and disciplined performance management across multiple delivery streams.

Working in close partnership with the Programme Manager (who leads day-to-day project governance and delivery execution), this role ensures that all elements of the business are aligned to deliver sustainable, high-quality, and profitable outcomes.

• Own and deliver against a project-based P&L, ensuring revenue, margin, and cash targets are achieved
• Integrate performance across key pillars (Programme Management, Engineering, Commercial, and Sales) to ensure joined-up execution of the business plan
• Ensure that healthy project performance translates into sustained P&L success
• Prepare and manage budgets, resource plans, and business forecasts to support the achievement of business objectives
• Ensure proposed opportunities and commitments are rigorously assessed against business capability, resource availability, delivery capacity, and commercial objectives before acceptance

• Work in close partnership with the Programme Manager to ensure effective governance, controls, and delivery standards are embedded across all work packages
• Maintain senior-level oversight of project performance, ensuring delivery against quality, schedule, and budget expectations
• Define and oversee portfolio-level KPIs and performance metrics, ensuring clear visibility of trends and risks
• Ensure early escalation and intervention where projects show signs of distress

Note:

The Programme Manager leads day-to-day delivery governance; this role ensures the system is working effectively and delivering outcomes.

• Lead monthly forecasting, reporting, and financial reviews, ensuring outputs are accurate, insightful, and decision-ready
• Maintain a strong grip on cost, margin, revenue, and cash performance across the portfolio
• Ensure all reporting is high quality and suitable for senior stakeholder engagement
• Provide analysis and recommendations to support informed business decision-making and continuous improvement

• Ensure appropriate oversight and assurance of NEC4 contract administration across the portfolio
• Work with Commercial and Programme teams to ensure robust management of change, risk, and commercial positions
• Support commercial teams in the negotiation and management of contract amendments, compensation events, variations, and associated commercial positions
• Maintain a balanced approach that protects the business while supporting collaborative and strategic client relationships

• Build and maintain strong relationships with client stakeholders at programme and commercial levels
• Support the development of a pipeline of work packages and framework opportunities in collaboration with Account Managers
• Support the development, review, and…