Summary  
Automating the extension of dynamic formulas to generate a 12-period time series forecast and comparing parameterized scenarios, with iterative validation to ensure cell references stay in sync.  

General domain of usage  
Financial forecasting in spreadsheets



In this chapter, you expand your model across time.

You move from single calculations to a full 12-month forecast and compare different pricing strategies side by side.



Start by asking Copilot to generate a new sheet with monthly projections.

Use your historical data to forecast subscriber count and profit for the next 12 months, assuming no changes.

This gives you a stable baseline to compare against.

Create the Baseline Forecast

Next, introduce alternative pricing strategies.

Use your Pricing Matrix to create:

- A max profit scenario;
- A max audience scenario.

Copilot builds projections for each case, so you can compare outcomes across the full year.

Add Scenario Comparisons


Check the results carefully.

If something looks off, it usually means Copilot lost context or used incorrect assumptions. In this case, churn was treated as a fixed value instead of a dynamic formula.

Validate the Forecast Logic


Guide Copilot with precise instructions.

Point it to the correct formulas and force it to reuse the logic from your assumptions model. Once corrected, the forecast aligns with your expected results.

Correct the Model

Discover how to use Excel with Copilot to solve real business problems. Explore practical workflows that turn messy data into structured, reliable systems. Learn how to build models, automate calculations, and generate insights without memorizing formulas. Understand how to guide Copilot, validate its output, and keep full control over your logic.

Explore the core setup and habits for working with Copilot in Excel. You configure your environment, learn how to write clear prompts, and apply safe workflows before using Copilot on real data. You focus on testing, verifying results, and protecting your files. These skills help you avoid mistakes and use Copilot with confidence further.

Focus on turning messy, inconsistent datasets into clean and usable data. You standardize headers, split combined fields, fix mixed formats, and remove duplicates using Copilot. Consider real-world scenarios and apply structured workflows to clean data safely.

Discover using Copilot to work with clean data and turn it into insights. You extract values, connect multiple datasets, handle errors, and build dynamic summaries. Learn to describe tasks in plain language while Copilot generates and applies the formulas.

Learn how to present data in a clear and interactive way. Create PivotTables, add slicers, build charts, and apply conditional formatting to highlight key insights. Combine all elements into a structured dashboard and use Copilot to support analysis, formatting, and presentation. 

Build a forecasting model using assumptions, pricing scenarios, and 12-month projections. Test different outcomes, guide Copilot through complex logic, and turn your analysis into a clear, decision-ready recommendation.

Turn your work into a reusable, product-like spreadsheet. Clean raw data, combine multiple sources into a single system, build automated reports, and package everything into a polished template with instructions that anyone can use.

Forecasting the Next 12 Months