New Meridian Scenario Planner turns MMM insights into budget moves marketers can actually use

The team behind Meridian, an open-source marketing mix model (MMM), has introduced Scenario Planner, a planning interface for marketers and analysts. The release focuses on turning Meridian's measurement outputs into inputs for budget and channel allocation decisions across marketing teams.

Key details: Meridian Scenario Planner for MMM insights

Scenario Planner adds a user interface on top of Meridian's existing MMM framework. It lets users test different budget scenarios and view estimated return on investment (ROI) in real time.

According to the announcement, Scenario Planner is intended for both decision makers and data scientists, with an interface designed to support shared planning sessions.

• The Scenario Planner interface is built for marketers and data scientists, according to the Meridian announcement.
• The tool does not require coding, allowing users without programming skills to work directly with MMM outputs.
• Users can adjust budget scenarios and immediately see updated ROI estimates based on Meridian model results.
• The interface is positioned as a bridge between analytics teams and planning teams within marketing organizations.
• Meridian remains open source, while Scenario Planner focuses on making its insights more accessible to non-technical stakeholders.

By connecting marketing teams with Scenario Planner, the Meridian announcement states that measurement insights can feed directly into business planning. Meridian has emphasized transparency in its MMM approach, and Scenario Planner is presented as an extension of that focus, providing easier access to those insights for a broader group of users.

Background context: connecting MMM outputs to decisions

A Harvard Business Review Analytic Services report from October 2025 found that nearly 40% of marketers surveyed face challenges using MMM outputs. The report notes that many organizations struggle to link model findings to real-world business decisions.

Marketing mix modeling is a statistical approach that uses historical marketing and sales data to estimate channel effectiveness. Companies use MMM to gauge the impact of media, promotions, and other variables on revenue or conversions.

The Meridian team positioned its open-source MMM as a response to long-standing concerns about transparency in measurement. Since Meridian's introduction, the project has focused on making marketing measurement more accessible beyond technical specialists.

Scenario Planner continues this focus by shifting from primarily retrospective reporting to forward-looking scenario planning. The tool is intended to connect Meridian's modeled insights with collaborative budgeting discussions, regardless of participants' technical skills.

Source citations

Information in this article is based on a Meridian announcement titled "New Meridian tool puts MMM insights directly in marketers' hands." The statistic on marketer challenges using MMM outputs comes from a Harvard Business Review Analytic Services report dated October 2025.