The level of protection for an information asset should be based on the impact to the business function that depends on the asset. The impact to the business function reflects the value and criticality of the information asset to the organization, and the potential consequences of its loss, compromise, or unavailability. The impact to the business function can be measured in terms of financial, operational, reputational, legal, or strategic effects. The higher the impact, the higher the level of protection required.
Impact on information security program, cost of controls, and cost to replace are not the best factors to provide guidance when deciding the level of protection for an information asset. Impact on information security program is a secondary effect that depends on the impact to the business function. Cost of controls and cost to replace are important considerations for implementing and maintaining the protection, but they do not determine the level of protection needed. Cost of controls and cost to replace should be balanced with the impact to the business function and the risk appetite of the organization. References = CISM Certified Information Security Manager Study Guide, Chapter 2: Information Risk Management, page 671; CISM Foundations: Module 2 Course, Part One: Information Risk Management2; CISM Review Manual 15th Edition, Chapter 2: Information Risk Management, page 693
When deciding the level of protection for an information asset, the most important factor to consider is the impact to the business function. The value of the asset should be evaluated in terms of its importance to the organization's operations and how its security posture affects the organization's overall security posture. Additionally, the cost of implementing controls, the potential impact on the information security program, and the cost to replace the asset should be taken into account when determining the appropriate level of protection for the asset.