Don't
- Forecast to the wall (most budgets provide fewer and fewer projections as the end budget date draws near)
- Confuse forecasts with targets (be realistic with forecasts, optimistic with targets)
- Insist on forecast accuracy in an unpredictable world (forecasts are a best guess at most)
- Rely on Excel spreadsheets (instead, try to find a way to budget/forecast in the accounting software)
- Engage in excessive detail
Do
- Use a rolling 12 month forecast (update every quarter)
- Focus on critical drivers (rather than excessive detail)
- Use different time horizons for different decisions
- Match forecast with ability to see
- Move to advance planning (such as scenario planning)
LEAN budgeting involves changing from a static budget to a dynamic one, and in doing so, shortens the amount of time and resources spent on budgeting.
A good resource for LEAN accounting is, "Real Numbers: Management Accounting in a Lean Organization," by Jean E. Cunningham, Orest J. Fiume, and Emily Adams.