KPI Tree

Metric Definition

ART = Total Time Between Customer Messages and Agent Replies / Total Number of Agent Replies
Total Time Between Customer Messages and Agent RepliesThe sum of all wait durations between each customer message and the subsequent agent reply across all conversations in the period
Total Number of Agent RepliesThe total count of agent replies sent in response to customer messages during the period

Average reply time (ART)

Average reply time measures the mean elapsed time between a customer sending a message and an agent responding within an ongoing support conversation. Unlike first response time, which covers only the initial reply, ART tracks responsiveness throughout the entire interaction, capturing the experience customers have after the conversation has started.

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What is average reply time?

Average reply time (ART) is the mean time a customer waits between sending a message within an active support conversation and receiving a reply from an agent. It applies to all asynchronous and semi-synchronous channels: email, live chat, in-app messaging, and social media. For phone support, the equivalent concept is hold time or transfer wait time.

ART is distinct from first response time (FRT), which only measures the wait for the initial reply. ART covers every subsequent exchange within the ticket. This distinction matters because many teams optimise FRT aggressively but neglect ongoing responsiveness. A team might reply within 2 minutes to the initial message but take 4 hours to respond to the customer's follow-up. From the customer's perspective, the slow follow-up is just as frustrating as a slow first response.

The metric captures a critical dimension of the support experience: momentum. When replies come quickly, the conversation flows and issues move toward resolution. When replies are slow, customers lose context, repeat information, and increasingly feel that their issue is not being prioritised. Research consistently shows that reply speed within an ongoing conversation is a stronger driver of satisfaction than the initial response time alone.

ART also affects operational efficiency. Slow replies extend ticket lifetimes, increase the ticket backlog, and raise the probability that customers will send additional messages asking for updates, further increasing the workload.

ART should be measured only during business hours unless your team provides 24/7 support. Including overnight or weekend hours in the calculation inflates the metric and hides genuine responsiveness problems during operating hours.

How to calculate average reply time

For each agent reply in a conversation, measure the elapsed time since the customer's preceding message. Sum those durations across all conversations, then divide by the total number of agent replies. Most helpdesk platforms provide ART as a standard report metric, though the label varies: "average reply time", "median response time", or "reply speed" are common.

Be aware of what your platform includes and excludes. Some tools count only human agent replies; others include automated responses. Some measure calendar time; others measure business hours only. Standardise your definition and apply it consistently.

Measurement approachAdvantageConsideration
Mean ARTSimple to calculate and widely understoodOutliers (very long waits on a few tickets) can skew the average significantly
Median ARTResistant to outlier distortionMay hide a long tail of poor experiences affecting a meaningful percentage of customers
P90 ARTReveals the experience of the worst-served 10% of customersUseful as a complementary metric alongside the median to ensure no segment is neglected

Decomposing reply time with a metric tree

Reply time is influenced by factors on both the demand side (how many messages arrive and when) and the supply side (how many agents are available and how quickly they can respond). A metric tree makes these factors visible.

The tree reveals that slow reply times can originate from very different causes. If the queue is the bottleneck, the fix is staffing or workload management. If agents are available but research takes time, the fix is better tooling and knowledge resources. If routing sends tickets to the wrong queue, the fix is classification and assignment logic.

Without the tree, a manager seeing slow ART might default to "we need more agents." With the tree, they can see that the problem is actually concentrated during a specific shift, or on a specific ticket category that requires cross-team input, and apply a targeted fix.

Average reply time benchmarks

ChannelGood ARTAcceptable ARTNeeds improvement
Live chatUnder 1 minute1 to 3 minutes5+ minutes
In-app messagingUnder 5 minutes5 to 15 minutes30+ minutes
EmailUnder 2 hours2 to 8 hours24+ hours
Social mediaUnder 30 minutes30 to 60 minutes4+ hours

Customer expectations for reply speed vary dramatically by channel. A 10-minute reply in live chat feels like an eternity. The same delay in email is excellent. Always set ART targets per channel rather than using a single blended target.

How to reduce average reply time

  1. 1

    Align staffing to demand patterns

    Analyse message volume by hour, day of week, and season. Schedule shifts so that agent availability matches inbound volume. Even a small mismatch during peak hours cascades into long reply times for the rest of the day.

  2. 2

    Set and enforce concurrent conversation limits

    Agents handling too many conversations simultaneously cannot reply quickly to any of them. Set reasonable concurrency limits based on complexity. For live chat, 2 to 3 simultaneous conversations is typical. For asynchronous messaging, higher limits work if response time targets are adjusted accordingly.

  3. 3

    Automate acknowledgements and status updates

    When an agent cannot reply immediately because they are researching the issue, an automated acknowledgement reduces perceived wait time. A message such as "We are looking into this and will reply within 30 minutes" sets expectations and reduces follow-up messages.

  4. 4

    Pre-build response templates for common follow-ups

    Many replies within a conversation are variations on common themes: requesting information, confirming a fix, providing next steps. Pre-built templates that agents can personalise reduce composition time from minutes to seconds.

  5. 5

    Prioritise queues based on conversation age and SLA

    Ensure that conversations with the oldest unanswered customer messages surface to the top of the queue. SLA-aware routing prevents situations where new conversations receive immediate replies whilst ongoing ones languish.

Tracking ART with KPI Tree

KPI Tree lets you model average reply time alongside first response time, average resolution time, and customer satisfaction score to build a complete picture of support responsiveness. Decompose ART by channel, team, shift, and issue type to identify exactly where delays concentrate.

Connect ART to its upstream drivers, staffing levels and workload distribution, and its downstream impacts, ticket lifetime and CSAT scores. This end-to-end view ensures that improvements in reply speed are reflected in customer outcomes, not just operational dashboards. Each node in the tree can be owned by the responsible team, making responsiveness a shared operational goal.

Related metrics

First Contact Resolution

Support effectiveness

Operations Metrics

Metric Definition

FCR Rate = (Issues Resolved on First Contact / Total Issues Handled) × 100

First contact resolution measures the percentage of customer enquiries resolved during the first interaction without requiring follow-up contacts, transfers, or escalations. It is the single most influential metric for customer satisfaction in support operations.

View metric

Customer Satisfaction Score

CSAT

Product Metrics

Metric Definition

CSAT = (Satisfied Responses / Total Responses) × 100

Customer satisfaction score measures how satisfied customers are with a specific interaction, product, or experience. Unlike NPS which measures loyalty, CSAT captures satisfaction at a moment in time, making it ideal for evaluating specific touchpoints in the customer journey.

View metric

Customer Effort Score

CES

Product Metrics

Metric Definition

CES = Sum of All Effort Ratings / Number of Responses

Customer effort score measures how much effort a customer had to exert to accomplish a goal with your product or service. Research shows that reducing effort is more predictive of customer loyalty than increasing satisfaction, making CES a powerful complement to NPS and CSAT.

View metric

Net Promoter Score

NPS

Product Metrics

Metric Definition

NPS = % Promoters - % Detractors

Net Promoter Score measures customer loyalty by asking how likely a customer is to recommend your product or service. It is the most widely used customer experience metric, providing a single number that captures sentiment and predicts growth through word-of-mouth.

View metric

Improve reply speed across every channel

Build a support responsiveness tree that decomposes reply time by channel, shift, and team. Connect it to customer satisfaction and resolution metrics to ensure faster replies translate into better outcomes.

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