Digital queue, walk-in, and arrival-order glossary

Terms

Virtual queue

An arrangement in which the customer joins the line digitally (via QR code, link, or kiosk) without having to wait physically on site.

Unlike a traditional in-person queue, a virtual queue lets the customer wait wherever they like — at home, in the car, at another business — and get called via WhatsApp, SMS, or push notification. Ordering (FIFO or priority) follows the same rules as a physical line, but the customer is freed from the venue until their turn.

How it works

FIFO (First In, First Out)

Service policy by arrival order: whoever arrives first is served first.

FIFO is the default for most physical and virtual queues. It ignores urgency or priority labels — every customer is handled in arrival order. In Brazilian establishments under Law 10.048, FIFO coexists with a priority queue (elderly, pregnant, persons with disabilities) that jumps ahead.

Walk-in

A customer who arrives without an appointment, expecting to be served in arrival order.

The opposite of a scheduled customer (reservation, booking, appointment). Bars, peak-hour restaurants, barbershops without booking, clinic follow-ups, and lab sample-collection counters operate predominantly in walk-in mode. Virtual queues are the standard tool to organize modern walk-in flow.

QR code check-in

Mechanism in which the customer scans the business's QR code and joins the queue automatically through a short form.

The QR code points to a public URL bound to that business's queue. Modern phone cameras (Android and iPhone) detect the code without a dedicated reader. No install required on the customer side — the phone browser is enough. QRs may be static (always the same) or dynamic (regenerated per session).

Comparison: QR vs paper tickets

Numbered ticket

Sequential identifier assigned to the customer at check-in, usually shown on screen and announced when called.

The ticket number is incremented for each new customer. It serves three purposes: privacy on the public call (announcing 'Ticket 42' instead of a full name), visual ordering on the queue display, and giving the customer feedback on how many people are ahead.

Average wait time

Estimate of how long each customer will wait before being served, computed from the business's own history.

Calculated by dividing total historical service time by service count over the same period, adjusted for time of day and day of week. Shown to the customer at check-in to calibrate expectations and reduce frustration. One of the most important KPIs in queue operations.

Priority queue

A parallel queue serving with precedence the groups protected by Brazilian Law 10.048: elderly (60+), pregnant women, nursing mothers, persons with disabilities, and people with infants.

In Brazilian public and private establishments serving the public, Law 10.048/2000 mandates priority service to those groups. The priority queue overrides FIFO and has its own order. Priority service must be visible and controlled, and can be audited by consumer-protection bodies.

Law 10.048/2000 (Brazil)

Brazilian law granting priority service to the elderly, pregnant women, persons with disabilities, and people with infants in public-facing establishments.

Originally focused on public transport, Law 10.048 was extended by Law 10.741/2003 (Elderly Statute) and Decree 5.296/2004. Today, any establishment serving the public (clinics, banks, supermarkets, government offices) must offer signed and operational priority service. Digital queue systems must support recording and signaling that priority.

No-show

A customer who joined the queue or made a reservation but doesn't show up when called.

Classic metric in queue and reservation operations. In virtual queues, no-show rates tend to be lower than with paper tickets because the customer receives automatic reminders before being called. Businesses can define a tolerance window before removing the customer and calling the next.

TTS (Text-to-Speech)

Technology that converts text to synthesized speech, used in queue displays to announce calls out loud.

On queue TV displays, TTS automatically reads the ticket and customer name aloud ('Ticket 42, Diego'). It solves two problems: accessibility (people with vision impairment and the elderly with reading difficulty hear the call) and noisy environments (busy reception, large waiting room). Runs directly in the browser via the Web Speech API, with no external cost.

Kiosk mode

A simplified check-in interface running on a device kept by the business (tablet, computer) for customers without a phone.

Kiosk is a dedicated page (no login, no outside navigation) designed to live on a reception tablet. A customer without a phone uses the tablet, checks in, and gets a printed or digital ticket. It keeps the virtual-queue flow without excluding customers who don't use smartphones.

Queue TV display

Public screen installed at reception or in the waiting area, showing the live queue, upcoming calls, and stats.

Replaces the traditional digital ticket dispenser (paper roll plus LED display). Shows the list of who's waiting, who's in service, how many were served today, and average service time. Updates in real time via WebSocket. Can be embedded on a Smart TV, tablet, monitor with mini-PC, or kiosk.

NPS (Net Promoter Score)

Satisfaction metric measuring on a 0-10 scale how likely a customer is to recommend the business to someone else.

Although Lyne uses a simplified version (1-5 stars instead of 0-10), the concept is the same: capture satisfaction at the end of service, while the experience is fresh. Crossing NPS with wait time is one of the most useful diagnostics in queue operations.

Webhook

A notification mechanism in which the system fires an HTTP POST to a customer-defined URL when an event happens.

In queue contexts, the business configures a URL and Lyne dispatches data whenever a customer joins the queue, is called, is served, or rates the visit. It allows integration with EHR, CRM, ERP, or spreadsheets without polling. The standard mechanism for lightweight integration, simpler than a traditional REST API.

REST API

A programmatic interface allowing other systems to create, read, update, and remove queue resources.

Unlike webhooks (one-way, from server to client), REST APIs are two-way: the external system reads and writes. On Lyne's Clinic plan, the customer gets an API key to pull the queue into their EHR, create entries remotely, or mark service via other software.

White-label

A product mode in which the platform brand (Lyne) is removed or replaced by the end customer's brand.

Useful for larger networks, franchises, and operations that don't want to expose the queue tool's brand to the patient. Includes a custom logo on WhatsApp messages, the TV display, and public pages. Available on Lyne's Clinic plan.

LGPD (Brazilian Law 13.709/2018)

Brazil's General Personal Data Protection Law, regulating personal data processing in the country.

Applied to Lyne, LGPD requires a legal basis for processing (legitimate interest for queue data), minimum-necessary retention, deletion rights for the data subject, hosting with security guarantees, and a designated DPO. Lyne stores only name and WhatsApp, with short retention and a DPO at [email protected].

Encaixe (walk-in slot)

In clinics, a patient who shows up without an appointment and is served between scheduled patients when there's availability.

The most common virtual-queue use case in clinics: the unscheduled patient arrives, scans the QR, joins the queue, and the system shows reception who's waiting. Whenever a window opens between appointments, the receptionist calls the next walk-in. It cuts professional idle time and organizes the waiting room.