CX routing terms explained
Short description
Glossary of the most common routing and prioritization logics in customer service and contact center systems. Explains when each logic is used and how they are combined in practice.
When to use this
When setting up or auditing inbox, queue and workflow rules, when discussing routing setups with customers or partners, and to understand terminology from Genesys, Zendesk, Salesforce, NICE and similar platforms.
Terms
FIFO – First In, First Out Default logic. The oldest ticket or contact is handled first. Typical for phone queues, email queues and simple support inboxes.
LIFO – Last In, First Out The newest ticket is handled first. Rare as a primary logic, useful in specific contexts (for example same-day escalations or fresh live-chat requests).
WIFO – Weighted FIFO Like FIFO, but each ticket carries a weight (priority, skill, SLA, customer tier). Higher-weighted tickets are pulled forward even if they arrived later. Some systems call this "Work Item First Out".
SBR – Skill-Based Routing Tickets go to agents with the matching skill (language, product knowledge, billing topics, etc.). Prevents tickets from landing with unqualified agents.
Priority Routing Routing by defined priority: VIP customers, escalations or premium tiers first. Usually combined with FIFO as a tie-breaker.
Round Robin Cycle-based distribution. Each available agent gets the next case in turn. Provides even load but ignores current occupancy.
Least Occupied The case goes to the agent with the lowest current load. Produces more balanced quality than pure round robin.
Longest Idle The case goes to the agent who has been idle the longest. Avoids individual agents sitting without work.
AI Routing Machine learning–based assignment based on sentiment, language, complexity, expected resolution probability or agent performance.
Sticky Routing A returning customer is automatically routed back to the agent who handled them last. Improves context continuity but can create bottlenecks when the agent is unavailable.
Omnichannel Routing Cross-channel routing: voice, chat, email, social and messaging all run through the same routing logic. Prevents duplicate handling and uneven load across channels.
SLA-Based Routing Tickets close to breaching SLA are pulled forward. Protects against violations of contractual response or resolution times.
Queue Priority Some queues are inherently more important than others (for example "Retention" over "General"). Usually layered on top of skill and priority.
How this is combined in practice
Modern CX platforms layer several logics. A typical setup:
FIFO as the base order.
Skill-based routing on top, so only matching agents are eligible.
Priority and SLA on top, to pull VIPs and critical deadlines forward.
Example: a ticket arrives later than others, but the customer is VIP, requires German-speaking handling, and the SLA expires in five minutes. Even though it arrived later, this ticket is assigned first.
Notes / best practices
Too many routing layers make setups hard to maintain. FIFO + skill + priority covers most cases.
Use sticky routing only when agents are reliably available, otherwise it creates wait times.
SLA-based routing depends on clean SLA fields per ticket. Without clean data it adds no value.
Vendors do not always use these terms identically. During audits or migrations, verify the exact definition per system (for example "WIFO" in Genesys vs. other platforms).