Best modern FP&A software: Runway vs. Abacum vs. Mosaic vs. Causal

As companies grow, so does the complexity of their decisions. Forecasts get harder to update, spreadsheets start to crack under the weight, and Finance teams spend more time reconciling inputs than testing outcomes.

Modern FP&A software changes that.

The best platforms unify your data, update your forecasts automatically, and let you model different futures — all in real time. But not all tools are built the same.

This guide compares four leading platforms — Runway, Abacum, Mosaic, and Causal — to help you understand which one actually fits your team’s needs.

Quick comparison: which FP&A tool fits your team?

• Runway is best for high-growth companies that want fast, intuitive modeling and team-wide collaboration.
• Abacum works well for mid-market finance teams with structured workflows.
• Mosaic is ideal for teams prioritizing dashboards, analytics, and finance-first views.
• Causal is a strong fit for formula-savvy teams that want a flexible, low-cost modeling layer.

Why modern FP&A tools exist in the first place

Traditional tools weren’t built for live planning. They were built for static reporting. You pull data from ERPs, paste it into spreadsheets, double-check every cell, and hope no one breaks a formula right before the board meeting.

The cost isn’t just time — it’s also accuracy and trust. That’s what suffers when teams rely on outdated, manual processes.

Modern platforms fix this by:

• Connecting directly to your source systems
• Updating forecasts automatically with actuals
• Turning “what if” questions into something you can test in seconds
• Making financial modeling accessible to every team, not just finance

Companies using modern FP&A tools make faster, clearer decisions. They stop asking “Is this number right?” and start asking “What should we do next?”

Platform deep dives

1. Runway: Built for the way modern teams actually plan

Runway doesn’t try to replicate spreadsheets. It rethinks them.

You get a real-time, collaborative, and intuitive planning interface — one that feels more like simulating a business than managing a model.

Core features:

• Human-readable formulas that anyone can understand
• Unlimited scenarios with side-by-side comparisons
• Dimensions for segmenting data by department, customer type, or location
• Real-time data updates from 750+ integrations
• Collaborative workflows and audit trails
• Reporting for interactive, board-ready dashboards

Strengths:

Runway feels more like Figma for finance — a planning layer every team can use. Changes ripple through your model instantly. And the logic is visible, not buried in formulas.

Ideal for:

Startups and growth-stage companies who need to plan often, change assumptions quickly, and keep everyone aligned.

Note that:

Runway benefits from having a clear model owner. Someone who knows the business well, and can connect the dots between logic, data, and decisions.

2. Abacum: Structured workflows for mid-market finance teams

Abacum is built for finance professionals who want to move beyond spreadsheets — but still want a familiar, Excel-style interface.

Core features:

• Collaborative workflow tools for finance teams
• Automated data gathering and transformation
• Budgeting and scenario planning capabilities
• Recently launched AI features for forecasting and report summaries

Strengths:

Abacum emphasizes structure. It works well for mid-market teams that have established processes, and want to manage them in a cleaner, more collaborative interface.

Ideal for:

Finance-led planning with limited cross-functional input. Teams that already have alignment on how things “should” work.

Note that:

For teams accustomed to Excel, the lack of native Excel integration might require an adjustment period.

3. Mosaic: The dashboard-first approach

Mosaic focuses on reporting, dashboards, and structured metrics. It’s less about simulation, and more about building a standardized view of company performance.

Core features:

• Collaborative budgeting with built-in workflows
• Automated reporting and metrics
• AI-powered insights
• Pre-made templates and model builders

Strengths:

If your top priority is visibility — and you want a platform that brings together finance and operational data in one view — Mosaic delivers.

Ideal for:

Small and mid-sized teams that want more clarity and less spreadsheet dependency.

Note that:

While Mosaic integrates with various systems, there may be limitations in connecting with less common applications.

4. Causal: Spreadsheet-native and formula-first

Causal treats planning like engineering: everything is a formula, every assumption is an input.

Core features:

• Works with ranges instead of fixed values to model multiple outcomes
• Live data integrations that automatically update models
• Interactive dashboards for sharing insights
• Visualization of expected variances (e.g., customer growth at different rates)

Strengths:

Causal gives you powerful modeling logic, especially if you want to test a wide range of outcomes, or build from scratch.

Best for:

Businesses that need to understand multiple possible outcomes rather than fixed scenarios, and teams comfortable with formula-based modeling.

How to choose the right FP&A software for you

Choosing a tool comes down to what kind of team you are — and what kind of decisions you want to make faster.

By company stage:

• Early-stage startups: Need cash flow visibility and fundraising tools. Runway's startup-focused features make it an excellent fit.
• Growth-stage companies: Require more sophisticated modeling and departmental collaboration. Runway or Abacum work well here.
• Established enterprises: May need deeper analytics and integration with complex systems. Mosaic or Abacum could be appropriate.

By team structure:

• If your finance team needs to collaborate closely with non-finance stakeholders, Runway's intuitive interface makes this seamless.
• For finance teams that operate more independently, Abacum or Causal might suffice.
• If you need to support complex data analysis, Mosaic's analytics focus could be valuable.

Key questions to ask

When comparing platforms, skip the feature checklist and ask:

1. Will our team actually use this — or will it become another tool we work around?
2. Can we get a working model live in weeks (not quarters)?
3. When things change, can we test ideas in real time?
4. Will our stakeholders understand what the model says, and why it matters?

For a detailed framework, see How to choose the right FP&A software.

Final recommendation

Each platform here does something well.

• Choose Runway if you want financial modeling that’s fast, collaborative, and easy to understand — for everyone at your company. It’s not just for startups — Runway also supports structured finance teams at scale with flexible models, deep integrations, and enterprise-grade security.
• Choose Abacum if you need structured workflows for an established finance team.
• Choose Mosaic if metrics reporting and dashboards are your biggest priority.
• Choose Causal if your team lives in formulas, and prefers full control over logic.

Book a demo to see how Runway makes finance accessible and understandable to everyone.