Exploring the role of a portfolio manager

When organisations run multiple projects and programmes simultaneously, the challenge is no longer just delivering individual initiatives, it’s making sure they all contribute to strategic business objectives. That’s where the portfolio manager comes in.

Portfolio managers provide the structure, visibility, and decision-making support needed to optimise value across a broad range of initiatives. In this blog, we take a closer look at the role of a portfolio manager, the skills they need, and how they support strategic oversight through alignment, governance, and assurance.

What does a portfolio manager do?

A portfolio manager is responsible for overseeing a collection of projects and programmes that together represent the organisation’s change initiatives. Unlike project or programme managers who focus on delivering specific outputs or outcomes, portfolio managers look across all change activity to ensure it aligns with strategic goals and delivers the greatest overall value.

This requires careful coordination between delivery teams, executives, and business units. The portfolio manager supports decision making by advising on priorities, managing competing demands for resources, and evaluating performance at a macro level. Their goal is not just to track delivery progress, but to ensure that benefits realisation across the portfolio is actively managed and measured.

In PRINCE2®-aligned organisations, portfolio managers often work closely with the Project Management Office (PMO) to develop frameworks for portfolio oversight and governance, helping ensure that decision-making is informed, consistent, and aligned to strategy.

Key responsibilities of a portfolio manager

Portfolio managers operate at the highest level of project governance. Their responsibilities often include:

• Defining the portfolio structure and ensuring it reflects business priorities
• Supporting investment decisions by evaluating project and programme proposals
• Monitoring delivery performance, risks, and interdependencies across the portfolio
• Managing resource capacity and ensuring alignment with organisational capability
• Facilitating executive reviews and providing data for strategic discussions
• Leading on portfolio assurance activities, including audits and benefit tracking
• Ensuring that projects align with strategic goals, and that the portfolio remains balanced

They may also play a role in developing business cases, setting strategic KPIs, and advising on whether initiatives should continue, pause, or close, ensuring agility in response to changing conditions.

Skills needed to succeed as a portfolio manager

Portfolio managers require a blend of strategic awareness, analytical ability, and governance expertise. They must be comfortable operating at senior levels, often working directly with boards, C-suite executives, and business sponsors.

Strategic thinking is essential. Portfolio managers must understand the organisation’s long-term goals and be able to evaluate how each project or programme contributes to them. This involves not just selecting the right mix of initiatives, but also knowing when to say no to projects that no longer serve the wider purpose.

Analytical skills are critical when reviewing business cases, risk profiles, and performance reports. Portfolio managers must be confident working with data to inform decisions and assess value.

Strong stakeholder engagement skills are also vital. As a central figure in portfolio governance, the portfolio manager must have influence across multiple layers of the organisation, managing expectations, facilitating prioritisation, and encouraging cross-functional alignment.

Finally, a working knowledge of structured approaches such as PRINCE2 is a significant advantage. These frameworks provide practical tools for managing change at scale, embedding assurance, and ensuring portfolio oversight and governance.

Portfolio manager vs programme or project manager

While these roles all contribute to change delivery, they differ in focus and scope.

A project manager is responsible for delivering a single product or outcome. A programme manager oversees a set of related projects aimed at achieving a specific transformation. The portfolio manager, however, looks across the entire landscape of change: prioritising, balancing, and aligning initiatives to maximise business value.

Think of the portfolio manager as the chief strategist of delivery. While others are focused on "doing things right", they focus on "doing the right things", ensuring that every investment aligns with strategic intent and contributes to broader success.

Find out more in our blog ‘Projects, programmes and portfolios: What’s the difference?’.

The value of strategic portfolio management

In organisations facing constant change and finite resources, the ability to prioritise and direct investment is more important than ever. Strategic portfolio management gives leaders the tools to make smarter choices, monitor progress, and adjust plans in response to shifting circumstances.

By managing dependencies, minimising duplication, and reallocating resources when needed, portfolio managers improve organisational agility and help ensure that time and money are spent where they’ll have the greatest impact.

Crucially, they also enable benefits realisation at portfolio level, making sure that the change programme as a whole delivers what was promised in terms of customer value, efficiency, innovation, or competitive advantage.

Why portfolio managers are essential to strategic delivery

As organisations scale and mature their delivery capability, the role of the portfolio manager becomes increasingly significant. They create the link between boardroom strategy and frontline delivery, helping senior leaders understand not just how projects are progressing, but how the collective effort is performing against the bigger picture.

With clear visibility, structured governance, and a strategic mindset, portfolio managers help organisations stay focused, aligned, and accountable for outcomes.

Whether coordinating transformation programmes or assessing long-term investment plans, portfolio managers play a vital role in aligning projects with strategic goals and keeping change on course.

Interested in developing your portfolio leadership skills? Explore our PRINCE2® training options to build capability in high-level decision making, benefits management, and structured governance. Alternatively, visit our main ILX Group website to learn more about our Management of Portfolios (MoP)® courses.