Creating an entitlement process and setting up milestones are steps that should be completed to hold service reps accountable to customer Service Level Agreements (SLAs). An entitlement process defines the timeline and steps required to deliver support to customers based on their entitlements. A milestone is a critical step in the support process that has a target date and time by which it must be completed. For example, a milestone could be responding to a customer within 24 hours or resolving a case within 5 days. By creating an entitlement process and setting up milestones, service reps can track their progress and ensure they meet the SLAs for each case. Verified References: Service Cloud Consultant Certification Guide & Tips, Set Up and Manage Entitlements and Milestones

Explanation
These are three best practices that should be used when deploying Salesforce functionality to production.
Planning and communicating the deployment to all users of the organization in advance will help avoid confusion and disruption, as well as ensure user adoption and feedback. Selecting a window of time when users will NOT be making changes to the organization will prevent data loss, conflicts, and errors during the deployment process. Ensuring all users refrain from logging into production for an entire day prior to deployment will minimize the risk of overwriting or corrupting the deployed functionality. Verified References: :
https://trailhead.salesforce.com/en/content/learn/modules/application-lifecycle-and-development-models/plan-an
:
https://trailhead.salesforce.com/en/content/learn/modules/application-lifecycle-and-development-models/deploy-

Skills-Based Routing is a feature that can enable service agents based in North America and Europe to respond to new leads created in Salesforce based on the language spoken. Skills-Based Routing is a feature that allows administrators to assign skills to agents and route work items, such as leads, cases, or chats, to the most qualified agent based on their skills, availability, and capacity. Skills-Based Routing can help ensure that leads are contacted by agents who speak the same language and provide faster and better service. Verified References: : https://help.salesforce.com/s/articleView?id=sf.omnichannel_skills_based_routing_overview.
htm&type=5 : https://help.salesforce.com/s/articleView?id=sf.omnichannel_skills_based_routing_setup.
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For providing executives and service managers with quick access to agent, team, and call center KPIs, utilizing Einstein Analytics for Service Cloud is recommended. This solution offers advanced analytics and visualization capabilities, enabling the creation of dashboards that provide real-time insights tailored to different organizational levels, based on their data access.

Explanation
Case assignment rules are rules that automatically assign cases to users or queues based on certain criteria.
You can create a case assignment rule to ensure that cases are owned by a user when they are closed, by setting the criteria to match the closed case status and the action to assign the case to the user who last modified it. This way, you can prevent cases from being closed while still owned by a queue. To correct the existing problem of hundreds of cases that are closed but still owned by a queue, you can use a data tool such as Data Loader or Import Wizard to update the owner field on those cases in bulk. Verified References: [Case Assignment Rules] and [Data Tools]