Which role/group is responsible for implementing the programme strategy?

The Programme Manager is responsible for the day-to-day leadership and management of the programme. This role translates the strategic direction set by the Programme Board (Sponsoring Group) into a concrete plan and oversees its execution. The Programme Manager ensures that the programme's projects and change activities are coordinated and integrated to deliver the intended outcomes and benefits, which is the essence of implementing the programme strategy. They are the central point of accountability for the successful delivery of the programme.

A. Programme office: The programme office is a support function responsible for providing standards, tools, and assurance; it facilitates but is not responsible for implementing the strategy.
B. Programme board: The programme board (or Sponsoring Group) is responsible for setting the strategic direction, providing governance, and making key decisions, but not for the day-to-day implementation.
D. Business change manager: The business change manager is responsible for ensuring changes are embedded into the business and that benefits are realized, which is a part of the strategy, but not its overall implementation.

AXELOS, "Managing Successful Programmes (MSP) 5th Edition" (2020).

Section 5.5, Programme manager: This section details the Programme Manager's responsibilities, stating they are "responsible for the day-to-day management of the programme on behalf of the sponsoring group" and for "leading and coordinating the team to deliver the defined outcomes." This directly corresponds to implementing the strategy.

Section 5.4, Sponsoring group (Programme Board): This section clarifies that the Sponsoring Group is "accountable for the programme's success" and provides "direction and leadership," which involves setting and approving the strategy, not implementing it directly.

Section 5.7, Programme office: This section describes the programme office as a "centre of excellence" that provides support, not as a role with implementation responsibility.