When determining the optimal IT service levels to support business, the most important factor is the cost/benefit to the business. This means that the IT service levels should be aligned with the business objectives, needs, and expectations, and that the benefits of providing a certain level of IT service should outweigh the costs of delivering it. The cost/benefit analysis should consider both the direct and indirect costs and benefits of IT service levels, such as the impact on customer satisfaction, revenue, productivity, quality, risk, compliance, innovation, and competitive advantage. A cost/benefit analysis can help IT managers justify their IT service level decisions and communicate them effectively to the business stakeholders. References := IT cost/benefit analysis: Why it matters and how to do it right, IT Support Levels Clearly Explained: L1, L2, L3 & More, IT support levels: definition, tiers and advantages, The Importance of Adopting Formal IT Service Management