There are several methods for forecasting cash flow, including:

1. Financial statement analysis: This method involves analyzing past financial statements to identify trends and patterns that can be used to predict future cash flow.
2. Budgeting: This method involves creating a budget for future expenses and revenue.
3. Time series analysis: This method involves using statistical techniques to analyze historical data and make predictions about future cash flow.
4. Simulation: This method involves creating a model of the business and using it to simulate different scenarios and predict future cash flow.
5. Indicator method: This method involves identifying key indicators of cash flow, such as sales or production levels, and using them to make predictions about future cash flow.

It’s also important to review and adjust the forecast regularly and take into account any changes in the business environment that may affect cash flow.