I Service Level Agreements sono un`important mezzo nella gestione di relazioni tra partner in una supply chain. Questa forma di contratto va al di lé dei tradizionali accordi scritti, come una dichiarazione di una specifica del servizio e del prezzo che verré pagato. Infatti lo SLA definisce la natura dei beni o dei servizi e il livello di quality che deve essere fornito. L`idea di un "accordo" o "agreement" é una visione mutuamente accordata da entrambe la parti coinvolte su come e cosa deve o dovré essere fornito. An SLA e vista come parte integrante dello sviluppo di una relazione tra il fornitore e l`acquirente ed essa riesce a formalizzarla in modo concreto. All`interno del contratto SLA sono specificati i doveri e la responsibility di entrambe la parti coinvolte, che devono essere rispettati per tutta la durata del contratto; inoltre il ruolo economico di questa tipologia di contratto é di abbassare i costi associati delle transazioni per avere una particolare quality del servizio fornito e di allocare i rischi e i costi di "produzione" e "consumo" del servizio. A web service level agreement (WSLA) is a standard for monitoring compliance with web services according to the service level agreement. It allows authors to indicate performance metrics assigned to a web application, desired performance goals, and actions to perform if performance is not achieved. Service level agreements can contain many service performance metrics with corresponding service level targets. A common case in IT services management is a call center or service desk. Among the metrics generally accepted in these cases are: SLAs often include many components, from the definition of services to the termination of the contract.  In order to ensure rigorous compliance with ALS, these agreements are often designed with specific lines of demarcation and the parties concerned must meet regularly to create an open communication forum.
Rewards and penalties that apply to the supplier are often set. Most ALS also leave room for regular (annual) revisions to make changes.  The fundamental advantage of cloud computing is the sharing of resources, supported by the underlying nature of a common infrastructure environment. SLAs therefore extend to the cloud and are offered by service providers as a service-based contract and not as a customer-based agreement. Measuring, monitoring and covering cloud performance is based on the final UX or its ability to consume resources. The disadvantage of cloud computing compared to ALS is the difficulty of determining the cause of service outages due to the complex nature of the environment. FP7 IRMOS also examined aspects of translation of ALS terms at the application level into resource-based attributes to bridge the gap between customer expectations and cloud provider resource management mechanisms.   The European Commission has presented a summary of the results of various ALS research projects (from specifications to monitoring, management and implementation).  The main point is to create a new level for the SOA network, cloud or middleware, capable of creating a trading mechanism between service providers and consumers.
For example, the EU-funded Framework SLA@SOI 7 research projectexplores aspects of multi-level, multi-supplier slas within service-based infrastructure and cloud computing, while another EU-funded project, VISION Cloud, has delivered results in terms of content-based ALS. Because applications are moved from dedicated hardware to the cloud, they must reach the same level of service, or even more sophisticated than conventional installations.