The underlying advantage of cloud computing is that of shared resources that are supported by the underlying nature of a common infrastructure environment. Therefore, SLAs span the entire cloud and are offered by service providers as a service agreement and not a customer-based agreement. Measuring, monitoring, and reporting on cloud performance is based on the final UX or its ability to consume resources. The disadvantage of cloud computing compared to SLAs is the difficulty of determining the cause of service interruptions due to the complexity of the nature of the environment. A Web Service Level Agreement (WSLA) is a standard for monitoring compliance with Service Level Agreements for Web services. Authors can specify the performance assigned to a web service application, the desired performance goals, and the actions to take if performance is not achieved. SLAs are widespread in the IT world, as businesses often depend on external services such as cloud computing, hosting, etc. However, almost any business relationship can be settled by a service level agreement. A service level agreement is a formal or informal contract between the end user of the service, internally or externally. It determines what the customer receives and specifies what is expected of the service provider. For example, Internet service providers and telecommunications companies will typically include service level agreements in the terms of their contracts with customers to define the service level(s) sold in plain language.
Wikipedia Service Level Agreements benefits both parties by providing absolute clarity on what can be expected from the business relationship. The key to the success of a service level agreement lies in the metrics applied to verify whether the service provider is meeting its end of business. It`s worth remembering the old saw: “You`ll have what you measure.” Since the late 1980s, SLAs have been used by fixed telecommunications operators. Today, SLAs are so prevalent that large organizations have many different SLAs in the company itself. Two different units in an organization write an SLA, one being the customer and the other the service provider. This approach helps maintain the same quality of service across different units of the organization and across multiple locations in the organization. This internal SLA scripting also makes it possible to compare the quality of service between an internal department and an external service provider.  A service level agreement (SLA) is an obligation between a service provider and a customer.
Particular aspects of the service – quality, availability, responsibilities – are agreed between the service provider and the service user.  The most common component of an SLA is that services must be provided to the customer as contractually agreed. For example, Internet service providers and telecommunications companies will typically include service level agreements in the terms of their contracts with customers to define the service level(s) sold in plain language. In this case, the SLA usually deconstructs a technical definition in the intermediate period between failures (MTBF), average repair time or mean recovery time (MTTR); identification of the party responsible for reporting errors or paying fees; responsibility for different data rates; throughput; Jitter; or similar measurable details. Many SLAs meet the specifications of the Information Technology Infrastructure Library when applied to IT services….