Security is a business-system decision, not only an interior-design choice. The supplied material combines a security reference with a player discussion about guards, so use your business requirements and in-game results to decide which measures are necessary.
Official Big Ambitions screenshot — source.
Check the business requirement and item category
Before buying security equipment or hiring a guard, review the business setup screen and current catalog. Confirm that the selected item or employee role meets the actual requirement for the property and business type.
Place security within the operating layout
Leave staff access and customer flow workable around security-related furniture. A complete-looking layout can still create service or cleaning problems if the operational space is blocked.
Reassess from observed outcomes
Monitor the business after opening. Community reports can explain options, but your version and business conditions determine whether a guard, camera, panel, or additional change is useful.