According to ASME guidelines, which of the following is not a method for ensuring crane stability?

Extending the boom is not considered a method for ensuring crane stability according to ASME guidelines. Instead, extending the boom can potentially create instability if not managed correctly, as it affects the crane's center of gravity and increases the leverage against it.

On the other hand, using outriggers is a standard method for enhancing stability by distributing the load of the crane and preventing tipping. Proper load positioning is critical as it involves placing the load in a manner that maintains balance and stability, particularly important when lifting heavy or off-center loads. Maintaining a firm footing is also essential because it ensures that the crane's base is secure and can support its weight without shifting or sinking. Collectively, these methods are focused on preserving the crane's stability while the crane is in operation.