diff --git a/app/assets/javascripts/app/controllers/_application_controller/form.coffee b/app/assets/javascripts/app/controllers/_application_controller/form.coffee
index 9d968be2e..eb9d6e69d 100644
--- a/app/assets/javascripts/app/controllers/_application_controller/form.coffee
+++ b/app/assets/javascripts/app/controllers/_application_controller/form.coffee
@@ -418,11 +418,11 @@ class App.ControllerForm extends App.Controller
 
       if !@constructor.fieldIsMandatory(field_by_name)
         field_by_name.attr('required', true)
-        field_by_name.parents('.form-group').find('label span').html('*')
+        field_by_name.closest('.form-group').find('label span').html('*')
         field_by_name.closest('.form-group').addClass('is-required')
       if !@constructor.fieldIsMandatory(field_by_data)
         field_by_data.attr('required', true)
-        field_by_data.parents('.form-group').find('label span').html('*')
+        field_by_data.closest('.form-group').find('label span').html('*')
         field_by_data.closest('.form-group').addClass('is-required')
 
   optional: (name, el = @form) ->
@@ -434,11 +434,11 @@ class App.ControllerForm extends App.Controller
 
       if @constructor.fieldIsMandatory(field_by_name)
         field_by_name.attr('required', false)
-        field_by_name.parents('.form-group').find('label span').html('')
+        field_by_name.closest('.form-group').find('label span').html('')
         field_by_name.closest('.form-group').removeClass('is-required')
       if @constructor.fieldIsMandatory(field_by_data)
         field_by_data.attr('required', false)
-        field_by_data.parents('.form-group').find('label span').html('')
+        field_by_data.closest('.form-group').find('label span').html('')
         field_by_data.closest('.form-group').removeClass('is-required')
 
   readonly: (name, el = @form) ->
diff --git a/app/assets/javascripts/app/controllers/_ui_element/sla_times.coffee b/app/assets/javascripts/app/controllers/_ui_element/sla_times.coffee
index 1a3fec95c..2bf72247d 100644
--- a/app/assets/javascripts/app/controllers/_ui_element/sla_times.coffee
+++ b/app/assets/javascripts/app/controllers/_ui_element/sla_times.coffee
@@ -8,9 +8,11 @@ class App.UiElement.sla_times
     item = $( App.view('generic/sla_times')(
       attribute: attribute
       first_response_time: params.first_response_time
+      response_time: params.response_time
       update_time: params.update_time
       solution_time: params.solution_time
       first_response_time_in_text: @toText(params.first_response_time)
+      response_time_in_text: @toText(params.response_time)
       update_time_in_text: @toText(params.update_time)
       solution_time_in_text: @toText(params.solution_time)
     ) )
@@ -26,12 +28,16 @@ class App.UiElement.sla_times
       row = element.closest('tr')
       if element.prop('checked')
         row.addClass('is-active')
+
+        if row.has('.js-updateTypeSelector').length > 0 && row.has('.js-updateTypeSelector:checked').length == 0
+          row.find('.js-updateTypeSelector:first').prop('checked', true)
       else
         row.removeClass('is-active')
 
         # reset data item
         row.find('.js-timeConvertFrom').val('')
         row.find('.js-timeConvertTo').val('')
+        row.find('.js-updateTypeSelector').attr('checked', false)
         row.find('.help-inline').empty()
         row.removeClass('has-error')
     )
@@ -42,12 +48,16 @@ class App.UiElement.sla_times
       inText = element.val()
 
       row = element.closest('tr')
-      row.find('.js-activateRow').prop('checked', true)
+
+      row
+        .find('.js-activateRow')
+        .prop('checked', true)
+        .trigger('change')
+
       row.addClass('is-active')
 
-      element
-        .closest('td')
-        .find('.js-timeConvertTo')
+      row
+        .find("[name='#{element.data('name')}']")
         .val(@toMinutes(inText) || '')
     )
 
@@ -56,9 +66,19 @@ class App.UiElement.sla_times
       $(e.currentTarget).closest('tr').find('.checkbox-replacement').click()
     )
 
+    # toggle update type on clicking around the element
+    item.find('.js-forward-radio').bind('click', (e) ->
+      elem = $(e.currentTarget).closest('p').find('.js-updateTypeSelector')
+
+      elem.prop('checked', true)
+      elem.trigger('change')
+    )
+
     # focus time input on clicking surrounding cell
     item.find('.js-focus-input').bind('click', (e) ->
-      $(e.currentTarget).find('.form-control').focus()
+      $(e.currentTarget)
+        .find('.form-control:visible')
+        .focus()
     )
 
     # show placeholder instead of 00:00
@@ -67,15 +87,36 @@ class App.UiElement.sla_times
         $(e.currentTarget).val('')
     )
 
+    # switch update/response times when type is selected accordingly
+    item.find('.js-updateTypeSelector').bind('change', (e) ->
+      element = $(e.target)
+      row = element.closest('tr')
+      row.find('.js-activateRow').prop('checked', true)
+      row.addClass('is-active')
+
+      row
+        .find('.js-timeConvertFrom')
+        .addClass('hidden')
+        .val('')
+
+      row
+        .find('.js-timeConvertTo')
+        .val('')
+
+      row
+        .find("[data-name='#{element.val()}_time']")
+        .removeClass('hidden')
+    )
+
     # set initial active/inactive rows
     item.find('.js-timeConvertFrom').each(->
       row = $(@).closest('tr')
       checkbox = row.find('.js-activateRow')
-      if $(@).val()
-        checkbox.prop('checked', true)
-        row.addClass('is-active')
-      else
-        checkbox.prop('checked', false)
+
+      return if !$(@).val()
+
+      checkbox.prop('checked', true)
+      row.addClass('is-active')
     )
 
     item
diff --git a/app/assets/javascripts/app/controllers/sla.coffee b/app/assets/javascripts/app/controllers/sla.coffee
index b3f50e1d3..1ab73b9d8 100644
--- a/app/assets/javascripts/app/controllers/sla.coffee
+++ b/app/assets/javascripts/app/controllers/sla.coffee
@@ -26,12 +26,6 @@ class Sla extends App.ControllerSubContent
       sortBy: 'name'
     )
     for sla in slas
-      if sla.first_response_time
-        sla.first_response_time_in_text = @toText(sla.first_response_time)
-      if sla.update_time
-        sla.update_time_in_text = @toText(sla.update_time)
-      if sla.solution_time
-        sla.solution_time_in_text = @toText(sla.solution_time)
       sla.rules = App.UiElement.ticket_selector.humanText(sla.condition)
       sla.calendar = App.Calendar.find(sla.calendar_id)
 
@@ -99,17 +93,4 @@ class Sla extends App.ControllerSubContent
       container:   @el.closest('.content')
     )
 
-  toText: (m) ->
-    m = parseInt(m)
-    return if !m
-    minutes = m % 60
-    hours = Math.floor(m / 60)
-
-    if minutes < 10
-      minutes = "0#{minutes}"
-    if hours < 10
-      hours = "0#{hours}"
-
-    "#{hours}:#{minutes}"
-
 App.Config.set('Sla', { prio: 2900, name: 'SLAs', parent: '#manage', target: '#manage/slas', controller: Sla, permission: ['admin.sla'] }, 'NavBarAdmin')
diff --git a/app/assets/javascripts/app/lib/mixins/view_helpers.coffee b/app/assets/javascripts/app/lib/mixins/view_helpers.coffee
index 64686fd3c..1ef955244 100644
--- a/app/assets/javascripts/app/lib/mixins/view_helpers.coffee
+++ b/app/assets/javascripts/app/lib/mixins/view_helpers.coffee
@@ -36,7 +36,7 @@ App.ViewHelpers =
     App.Utils.decimal(data, positions)
 
   # define time_duration / mm:ss / hh:mm:ss format helper
-  time_duration: (time) ->
+  time_duration: (time, show_seconds = true) ->
     return '' if !time
     return '' if isNaN(parseInt(time))
 
@@ -48,7 +48,7 @@ App.ViewHelpers =
     # Output like "1:01" or "4:03:59" or "123:03:59"
     mins = "0#{mins}" if mins < 10
     secs = "0#{secs}" if secs < 10
-    if hrs > 0
+    if hrs > 0 && show_seconds
       return "#{hrs}:#{mins}:#{secs}"
     "#{mins}:#{secs}"
 
diff --git a/app/assets/javascripts/app/models/sla.coffee b/app/assets/javascripts/app/models/sla.coffee
index 824db43cf..5724ada1f 100644
--- a/app/assets/javascripts/app/models/sla.coffee
+++ b/app/assets/javascripts/app/models/sla.coffee
@@ -1,5 +1,5 @@
 class App.Sla extends App.Model
-  @configure 'Sla', 'name', 'first_response_time', 'update_time', 'solution_time', 'condition', 'calendar_id'
+  @configure 'Sla', 'name', 'first_response_time', 'response_time', 'update_time', 'solution_time', 'condition', 'calendar_id'
   @extend Spine.Model.Ajax
   @url: @apiPath + '/slas'
   @configure_attributes = [
@@ -12,6 +12,7 @@ class App.Sla extends App.Model
     { name: 'updated_by_id',  display: 'Updated by',      relation: 'User', readonly: 1 },
     { name: 'updated_at',     display: 'Updated',         tag: 'datetime', readonly: 1 },
     { name: 'first_response_time',skipRendering: true },
+    { name: 'response_time',        skipRendering: true },
     { name: 'update_time',        skipRendering: true },
     { name: 'solution_time',      skipRendering: true },
   ]
diff --git a/app/assets/javascripts/app/views/generic/sla_times.jst.eco b/app/assets/javascripts/app/views/generic/sla_times.jst.eco
index 98fe6ea21..0c4fcda89 100644
--- a/app/assets/javascripts/app/views/generic/sla_times.jst.eco
+++ b/app/assets/javascripts/app/views/generic/sla_times.jst.eco
@@ -6,7 +6,7 @@
       <th><%- @T('Time') %> <span class="text-muted"><%- @T('in hours') %></span>
   </thead>
   <tbody>
-    <tr class="form-group">
+    <tr>
       <td class="u-positionOrigin">
         <label class="checkbox-replacement checkbox-replacement--fullscreen dont-grey-out">
           <input type="checkbox" class="js-activateRow" id="first_response_time" name="first_response_time_enabled">
@@ -16,25 +16,51 @@
       <td class="u-clickable js-forward-click">
         <div><%- @T('First Response Time') %></div>
         <p class="subtle"><%- @T('Timeframe for the first response.') %></p>
-      <td class="u-clickable js-focus-input">
+      <td class="u-clickable js-focus-input form-group">
         <input type="hidden" name="first_response_time" value="<%= @first_response_time %>" class="js-timeConvertTo">
         <input type="text" value="<%= @first_response_time_in_text %>" class="form-control form-control--small timeframe js-timeConvertFrom"  placeholder="hh:mm" name="first_response_time_in_text" data-name="first_response_time">
 
-    <tr class="form-group">
+    <tr>
       <td class="u-positionOrigin">
         <label class="checkbox-replacement checkbox-replacement--fullscreen dont-grey-out">
           <input type="checkbox" class="js-activateRow" id="update_time" name="update_time_enabled">
           <%- @Icon('checkbox', 'icon-unchecked') %>
           <%- @Icon('checkbox-checked', 'icon-checked') %>
         </label>
-      <td class="u-clickable js-forward-click">
-        <div><%- @T('Update Time') %></div>
-        <p class="subtle"><%- @T('Timeframe for every following response.') %></p>
       <td>
-        <input type="hidden" name="update_time" value="<%= @update_time %>" class="js-timeConvertTo">
-        <input type="text" value="<%= @update_time_in_text %>" class="form-control form-control--small timeframe js-timeConvertFrom" placeholder="hh:mm" name="update_time_in_text" data-name="update_time">
+        <div class="u-clickable js-forward-click">
+          <div><%- @T('Update Time') %></div>
+          <p class="subtle"><%- @T('Timeframe between agent updates or for an agent to respond.') %></p>
+        </div>
 
-    <tr class="form-group">
+        <p class="sla_radio_container js-forward-radio">
+          <label class="inline-label radio-replacement">
+            <input class="js-updateTypeSelector" type="radio" name="update_type" value="update" <% if @update_time: %>checked<% end %>>
+            <%- @Icon('radio', 'icon-unchecked') %>
+            <%- @Icon('radio-checked', 'icon-checked') %>
+            <span class="label-text"><%- @T('between agent updates') %></span>
+          </label>
+        </p>
+
+        <p class="sla_radio_container js-forward-radio u-clickable">
+          <label class="inline-label radio-replacement">
+            <input class="js-updateTypeSelector" type="radio" name="update_type" value="response" <% if @response_time: %>checked<% end %>>
+            <%- @Icon('radio', 'icon-unchecked') %>
+            <%- @Icon('radio-checked', 'icon-checked') %>
+            <span class="label-text"><%- @T('for an agent to respond') %></span>
+          </label>
+        </p>
+      <td class="form-group u-clickable js-focus-input u-clickable">
+        <span class="form-group">
+          <input type="hidden" name="update_time" value="<%= @update_time %>" class="js-timeConvertTo">
+          <input type="text" value="<%= @update_time_in_text %>" class="form-control form-control--small timeframe js-timeConvertFrom <% if @response_time: %>hidden<% end %>" placeholder="hh:mm" name="update_time_in_text" data-name="update_time">
+        </span>
+        <span class="form-group">
+          <input type="hidden" name="response_time" value="<%= @response_time %>" class="js-timeConvertTo">
+          <input type="text" value="<%= @response_time_in_text %>" class="form-control form-control--small timeframe js-timeConvertFrom <% if !@response_time: %>hidden<% end %>" placeholder="hh:mm" name="response_time_in_text" data-name="response_time">
+        </span>
+
+    <tr>
       <td class="u-positionOrigin">
         <label class="checkbox-replacement checkbox-replacement--fullscreen dont-grey-out">
           <input type="checkbox" id="solution_time" class="js-activateRow" name="solution_time_enabled">
@@ -44,7 +70,7 @@
       <td class="u-clickable js-forward-click">
         <div><%- @T('Solution Time') %></div>
         <p class="subtle"><%- @T('Timeframe for solving the problem.') %></p>
-      <td>
+      <td class="form-group u-clickable js-focus-input">
         <input type="hidden" name="solution_time" value="<%= @solution_time %>" class="js-timeConvertTo">
         <input type="text" value="<%= @solution_time_in_text %>" class="form-control form-control--small timeframe js-timeConvertFrom" placeholder="hh:mm" name="solution_time_in_text" data-name="solution_time">
 
diff --git a/app/assets/javascripts/app/views/sla/index.jst.eco b/app/assets/javascripts/app/views/sla/index.jst.eco
index 2f7adce89..8e0ee1bdf 100644
--- a/app/assets/javascripts/app/views/sla/index.jst.eco
+++ b/app/assets/javascripts/app/views/sla/index.jst.eco
@@ -34,15 +34,19 @@
       <div class="action-block action-block--flex">
         <div class="label"><%- @T('Escalation Times') %></div>
         <% if sla.first_response_time: %>
-          <%- sla.first_response_time_in_text %> <%- @T('hours') %> - <%- @T('First Response Time') %>
+          <%- @time_duration(sla.first_response_time, false) %> <%- @T('hours') %> - <%- @T('First Response Time') %>
+        <% end %>
+        <% if sla.response_time: %>
+          <br>
+          <%- @time_duration(sla.response_time, false) %> <%- @T('hours') %> - <%- @T('Response Time') %>
         <% end %>
         <% if sla.update_time: %>
           <br>
-          <%- sla.update_time_in_text %> <%- @T('hours') %> - <%- @T('Update Time') %>
+          <%- @time_duration(sla.update_time, false) %> <%- @T('hours') %> - <%- @T('Update Time') %>
         <% end %>
         <% if sla.solution_time: %>
           <br>
-          <%- sla.solution_time_in_text %> <%- @T('hours') %> - <%- @T('Solution Time') %>
+          <%- @time_duration(sla.solution_time, false) %> <%- @T('hours') %> - <%- @T('Solution Time') %>
         <% end %>
         <br>
       </div>
@@ -57,4 +61,4 @@
     </div>
   </div>
   <% end %>
-</div>
\ No newline at end of file
+</div>
diff --git a/app/assets/stylesheets/zammad.scss b/app/assets/stylesheets/zammad.scss
index 025d2a488..c7d1f28b7 100644
--- a/app/assets/stylesheets/zammad.scss
+++ b/app/assets/stylesheets/zammad.scss
@@ -13157,3 +13157,10 @@ span.is-disabled {
 .text-modules-box {
   max-height: 40vh;
 }
+
+.sla_times {
+  .sla_radio_container {
+    padding-top: 0.5em;
+    padding-left: 0.5em;
+  }
+}
diff --git a/app/models/core_workflow/custom/admin_sla.rb b/app/models/core_workflow/custom/admin_sla.rb
index 23702b0b6..c8fdce415 100644
--- a/app/models/core_workflow/custom/admin_sla.rb
+++ b/app/models/core_workflow/custom/admin_sla.rb
@@ -16,7 +16,13 @@ class CoreWorkflow::Custom::AdminSla < CoreWorkflow::Custom::Backend
   end
 
   def update_time_enabled
-    return 'set_mandatory' if params['update_time_enabled'].present?
+    return 'set_mandatory' if params['update_time_enabled'].present? && params['update_type'] == 'update'
+
+    'set_optional'
+  end
+
+  def response_time_enabled
+    return 'set_mandatory' if params['update_time_enabled'].present? && params['update_type'] == 'response'
 
     'set_optional'
   end
@@ -32,6 +38,7 @@ class CoreWorkflow::Custom::AdminSla < CoreWorkflow::Custom::Backend
     # make fields mandatory if checkbox is checked
     result(first_response_time_enabled, 'first_response_time_in_text')
     result(update_time_enabled, 'update_time_in_text')
+    result(response_time_enabled, 'response_time_in_text')
     result(solution_time_enabled, 'solution_time_in_text')
   end
 end
diff --git a/app/models/sla.rb b/app/models/sla.rb
index 5accf2d84..6575230f4 100644
--- a/app/models/sla.rb
+++ b/app/models/sla.rb
@@ -13,6 +13,8 @@ class Sla < ApplicationModel
 
   validates  :name, presence: true
 
+  validate   :cannot_have_response_and_update
+
   store      :condition
   store      :data
 
@@ -32,4 +34,12 @@ class Sla < ApplicationModel
     end
     fallback
   end
+
+  private
+
+  def cannot_have_response_and_update
+    return if response_time.blank? || update_time.blank?
+
+    errors.add :base, 'cannot have both response time and update time'
+  end
 end
diff --git a/db/migrate/20120101000010_create_ticket.rb b/db/migrate/20120101000010_create_ticket.rb
index 4d13807d5..5d5d5666f 100644
--- a/db/migrate/20120101000010_create_ticket.rb
+++ b/db/migrate/20120101000010_create_ticket.rb
@@ -446,6 +446,7 @@ class CreateTicket < ActiveRecord::Migration[4.2]
       t.references :calendar,                                   null: false
       t.column :name,                 :string, limit: 150,      null: true
       t.column :first_response_time,  :integer,                 null: true
+      t.column :response_time,        :integer,                 null: true
       t.column :update_time,          :integer,                 null: true
       t.column :solution_time,        :integer,                 null: true
       t.column :condition,            :text, limit: 500.kilobytes + 1, null: true
diff --git a/db/migrate/20210614063039_sla_add_response_time.rb b/db/migrate/20210614063039_sla_add_response_time.rb
new file mode 100644
index 000000000..ce609088d
--- /dev/null
+++ b/db/migrate/20210614063039_sla_add_response_time.rb
@@ -0,0 +1,13 @@
+# Copyright (C) 2012-2021 Zammad Foundation, http://zammad-foundation.org/
+
+class SlaAddResponseTime < ActiveRecord::Migration[5.2]
+  def change
+    return if !Setting.exists?(name: 'system_init_done')
+
+    change_table :slas do |t|
+      t.integer :response_time
+    end
+
+    Sla.reset_column_information
+  end
+end
diff --git a/lib/escalation.rb b/lib/escalation.rb
index 817c1a017..a41d3a8f3 100644
--- a/lib/escalation.rb
+++ b/lib/escalation.rb
@@ -97,7 +97,7 @@ class Escalation
   end
 
   def update_escalations
-    ticket.assign_attributes [escalation_first_response, escalation_update, escalation_close]
+    ticket.assign_attributes [escalation_first_response, escalation_response, escalation_update, escalation_close]
       .compact
       .each_with_object({}) { |elem, memo| memo.merge!(elem) }
 
@@ -105,7 +105,7 @@ class Escalation
   end
 
   def update_statistics
-    ticket.assign_attributes [statistics_first_response, statistics_update, statistics_close]
+    ticket.assign_attributes [statistics_first_response, statistics_response, statistics_update, statistics_close]
       .compact
       .each_with_object({}) { |elem, memo| memo.merge!(elem) }
   end
@@ -130,11 +130,41 @@ class Escalation
     }
   end
 
-  def escalation_update
+  def escalation_update_reset
+    return if skip_escalation? && !preferences.last_update_at_changed?(ticket)
+    return if sla.response_time.present? || sla.update_time.present?
+
+    { update_escalation_at: nil }
+  end
+
+  def escalation_response_timestamp
+    return if escalation_disabled? || ticket.agent_responded?
+
+    ticket.last_contact_customer_at
+  end
+
+  def escalation_response
+    return if sla.response_time.nil?
     return if skip_escalation? && !preferences.last_update_at_changed?(ticket)
 
-    nullify   = escalation_disabled? || ticket.agent_responded?
-    timestamp = nullify ? nil : ticket.last_contact_customer_at
+    timestamp = escalation_response_timestamp
+
+    {
+      update_escalation_at: timestamp ? calculate_time(timestamp, sla.response_time) : nil
+    }
+  end
+
+  def escalation_update_timestamp
+    return if escalation_disabled?
+
+    ticket.last_contact_agent_at || ticket.created_at
+  end
+
+  def escalation_update
+    return if sla.update_time.nil?
+    return if skip_escalation? && !preferences.last_update_at_changed?(ticket)
+
+    timestamp = escalation_update_timestamp
 
     {
       update_escalation_at: timestamp ? calculate_time(timestamp, sla.update_time) : nil
@@ -186,11 +216,39 @@ class Escalation
     }
   end
 
+  def skip_statistics_response?
+    return true if !forced? && !preferences.last_update_at_changed?(ticket)
+    return true if !sla.response_time
+
+    !ticket.agent_responded?
+  end
+
+  # ATTENTION: Recalculation after SLA change won't happen
+  # SLA change will cause wrong statistics in some edge cases.
+  # Since this changes `update_in_min` calculation to retain longest timespan.
+  # But it does not keep track of previous update times.
+  def statistics_response_applicable?(minutes)
+    ticket.update_in_min.blank? || minutes > ticket.update_in_min # keep longest timespan
+  end
+
+  def statistics_response
+    return if skip_statistics_response?
+
+    minutes = calculate_minutes(ticket.last_contact_customer_at, ticket.last_contact_agent_at)
+
+    return if !forced? && !statistics_response_applicable?(minutes)
+
+    {
+      update_in_min:      minutes,
+      update_diff_in_min: minutes ? (sla.response_time - minutes) : nil
+    }
+  end
+
   def skip_statistics_update?
     return true if !forced? && !preferences.last_update_at_changed?(ticket)
     return true if !sla.update_time
 
-    !ticket.agent_responded?
+    ticket.last_contact_agent_at.blank?
   end
 
   # ATTENTION: Recalculation after SLA change won't happen
@@ -201,10 +259,28 @@ class Escalation
     ticket.update_in_min.blank? || minutes > ticket.update_in_min # keep longest timespan
   end
 
+  def statistics_update_responses
+    ticket
+      .articles
+      .reverse
+      .lazy
+      .select { |article| article.sender&.name == 'Agent' && article.type&.communication }
+      .first(2)
+  end
+
+  def statistics_update_minutes
+    last_agent_responses = statistics_update_responses
+
+    from = last_agent_responses.second&.created_at || ticket.created_at
+    to   = last_agent_responses.first&.created_at
+
+    calculate_minutes(from, to)
+  end
+
   def statistics_update
     return if skip_statistics_update?
 
-    minutes = calculate_minutes(ticket.last_contact_customer_at, ticket.last_contact_agent_at)
+    minutes = statistics_update_minutes
 
     return if !forced? && !statistics_update_applicable?(minutes)
 
diff --git a/public/assets/tests/form_extended.js b/public/assets/tests/form_extended.js
index b4ce7be80..1ebc50a60 100644
--- a/public/assets/tests/form_extended.js
+++ b/public/assets/tests/form_extended.js
@@ -170,12 +170,15 @@ test('form checks', function() {
     first_response_time: '150',
     first_response_time_enabled: 'on',
     first_response_time_in_text: '02:30',
+    response_time: '',
+    response_time_in_text: '',
     solution_time: '',
     solution_time_enabled: undefined,
     solution_time_in_text: '',
     update_time: '45',
     update_time_enabled: 'on',
     update_time_in_text: '00:45',
+    update_type: 'update',
     working_hours: {
       mon: {
         active: true,
@@ -318,15 +321,90 @@ test('form checks', function() {
     first_response_time: '30',
     first_response_time_enabled: 'on',
     first_response_time_in_text: '00:30',
+    response_time: '',
+    response_time_in_text: '',
     solution_time: '',
     solution_time_enabled: undefined,
     solution_time_in_text: '',
     update_time: '',
     update_time_enabled: undefined,
     update_time_in_text: '',
+    update_type: undefined,
   }
   deepEqual(params, test_params, 'form param check')
 
+  // change sla times
+  el.find('#update_time').attr('checked', false)
+  el.find('[value=response]').click()
+  el.find('[name="response_time_in_text"]').val('4:30').trigger('blur')
+
+  var params = App.ControllerForm.params(el)
+  var test_params = {
+    priority1_id: '1',
+    priority2_id: ['1', '2'],
+    priority3_id: '2',
+    priority4_id: '2',
+    priority5_id: '1',
+    working_hours: {
+      mon: {
+        active: true,
+        timeframes: [
+          ['09:00','17:00']
+        ]
+      },
+      tue: {
+        active: true,
+        timeframes: [
+          ['00:00','22:00']
+        ]
+      },
+      wed: {
+        active: true,
+        timeframes: [
+          ['09:00','17:00']
+        ]
+      },
+      thu: {
+        active: true,
+        timeframes: [
+          ['09:00','12:00'],
+          ['13:00','17:00']
+        ]
+      },
+      fri: {
+        active: true,
+        timeframes: [
+          ['09:00','17:00']
+        ]
+      },
+      sat: {
+        active: false,
+        timeframes: [
+          ['10:00','14:00']
+        ]
+      },
+      sun: {
+        active: false,
+        timeframes: [
+          ['10:00','14:00']
+        ]
+      },
+    },
+    first_response_time: '30',
+    first_response_time_enabled: 'on',
+    first_response_time_in_text: '00:30',
+    response_time: '270',
+    response_time_in_text: '04:30',
+    solution_time: '',
+    solution_time_enabled: undefined,
+    solution_time_in_text: '',
+    update_time: '',
+    update_time_enabled: 'on',
+    update_time_in_text: '',
+    update_type: 'response'
+  }
+  deepEqual(params, test_params, 'form param check post response')
+
   /* empty params or defaults */
   $('#forms').append('<hr><h1>form condition check</h1><form id="form2"></form>')
   var el = $('#form2')
diff --git a/public/assets/tests/form_sla_times.js b/public/assets/tests/form_sla_times.js
index 0c1518ed0..57153d6a7 100644
--- a/public/assets/tests/form_sla_times.js
+++ b/public/assets/tests/form_sla_times.js
@@ -57,6 +57,30 @@ test("form SLA times highlights and shows settings accordingly", function(assert
   equal(firstRow.find('input[data-name=first_response_time]').val(), '')
   ok(secondRow.hasClass('is-active'))
   equal(secondRow.find('input[data-name=update_time]').val(), '04:00')
+  equal(secondRow.find('input[name=update_type]:checked').val(), 'update')
+
+  $('#forms').append('<hr><h1>SLA with response time set</h1><form id="form3a"></form>')
+
+  var el = $('#form3a')
+
+  var item = new App.Sla()
+  item.id = '123'
+  item.response_time = 180
+
+  new App.ControllerForm({
+    el:     el,
+    model:  item.constructor,
+    params: item
+  });
+
+  var firstRow = el.find('.sla_times tbody > tr:first')
+  var secondRow = el.find('.sla_times tbody > tr:nth-child(2)')
+
+  notOk(firstRow.hasClass('is-active'))
+  equal(firstRow.find('input[data-name=first_response_time]').val(), '')
+  ok(secondRow.hasClass('is-active'))
+  equal(secondRow.find('input[data-name=response_time]').val(), '03:00')
+  equal(secondRow.find('input[name=update_type]:checked').val(), 'response')
 })
 
 test("form SLA times clears field instead of 00:00", function(assert) {
diff --git a/spec/lib/escalation_spec.rb b/spec/lib/escalation_spec.rb
index 7d6a012ff..08d52ffeb 100644
--- a/spec/lib/escalation_spec.rb
+++ b/spec/lib/escalation_spec.rb
@@ -3,13 +3,18 @@
 require 'rails_helper'
 
 RSpec.describe ::Escalation do
-  let(:instance) { described_class.new ticket, force: force }
+  let(:instance)              { described_class.new ticket, force: force }
   let(:instance_with_history) { described_class.new ticket_with_history, force: force }
+  let(:instance_with_open)    { described_class.new open_ticket_with_history, force: force }
+
   let(:ticket)   { create(:ticket) }
   let(:force)    { false }
-  let(:sla)      { nil }
-  let(:sla_247)  { create(:sla, :condition_blank, first_response_time: 60, update_time: 60, solution_time: 75, calendar: create(:calendar, :'24/7')) }
-  let(:calendar) { nil }
+  let(:calendar) { create(:calendar, :'24/7') }
+
+  let(:sla_247)          { create(:sla, :condition_blank, solution_time: 75, calendar: calendar) }
+  let(:sla_247_response) { create(:sla, :condition_blank, first_response_time: 30, response_time: 45, solution_time: 75, calendar: calendar) }
+  let(:sla_247_update)   { create(:sla, :condition_blank, first_response_time: 30, update_time: 60, solution_time: 75, calendar: calendar) }
+
   let(:ticket_with_history) do
     freeze_time
     ticket = create(:ticket)
@@ -252,7 +257,7 @@ RSpec.describe ::Escalation do
 
     # https://github.com/zammad/zammad/issues/3140
     it 'customer contact sets #update_escalation_at' do
-      sla_247
+      sla_247_response
       ticket
       create(:ticket_article, :inbound_email, ticket: ticket)
 
@@ -261,7 +266,7 @@ RSpec.describe ::Escalation do
 
     context 'with ticket with sla and customer enquiry' do
       before do
-        sla_247
+        sla_247_response
         ticket
 
         travel 10.minutes
@@ -289,34 +294,120 @@ RSpec.describe ::Escalation do
     let(:force) { true } # initial calculation
 
     it 'returns attribute' do
-      sla_247
+      sla_247_response
       allow(instance_with_history).to receive(:escalation_disabled?).and_return(false)
       result = instance_with_history.send(:escalation_first_response)
-      expect(result).to include first_response_escalation_at: 60.minutes.ago
+      expect(result).to include first_response_escalation_at: 90.minutes.ago
     end
 
     it 'returns nil when no sla#first_response_time' do
-      sla_247.update! first_response_time: nil
+      sla_247_response.update! first_response_time: nil
       allow(instance_with_history).to receive(:escalation_disabled?).and_return(false)
       result = instance_with_history.send(:escalation_first_response)
       expect(result).to include(first_response_escalation_at: nil)
     end
   end
 
-  describe '#escalation_update' do
-    it 'returns attribute' do
+  describe '#escalation_update_reset' do
+    it 'resets to nil when no sla#response_time and sla#update_time' do
       sla_247
-      ticket_with_history.last_contact_customer_at = 2.hours.ago
       allow(instance_with_history).to receive(:escalation_disabled?).and_return(false)
-      result = instance_with_history.send(:escalation_update)
-      expect(result).to include update_escalation_at: 60.minutes.ago
+      result = instance_with_history.send(:escalation_update_reset)
+      expect(result).to include(update_escalation_at: nil)
+    end
+
+    it 'returns nil when no sla#response_time' do
+      sla_247_update
+      allow(instance_with_history).to receive(:escalation_disabled?).and_return(false)
+      result = instance_with_history.send(:escalation_update_reset)
+      expect(result).to be_nil
     end
 
     it 'returns nil when no sla#update_time' do
-      sla_247.update! update_time: nil
+      sla_247_response
       allow(instance_with_history).to receive(:escalation_disabled?).and_return(false)
-      result = instance_with_history.send(:escalation_update)
-      expect(result).to include(update_escalation_at: nil)
+      result = instance_with_history.send(:escalation_update_reset)
+      expect(result).to be_nil
+    end
+  end
+
+  describe '#escalation_response' do
+    it 'returns attribute' do
+      sla_247_response
+      ticket_with_history.last_contact_customer_at = 2.hours.ago
+      allow(instance_with_history).to receive(:escalation_disabled?).and_return(false)
+      result = instance_with_history.send(:escalation_response)
+      expect(result).to include update_escalation_at: 75.minutes.ago
+    end
+
+    it 'returns nil when no sla#response_time' do
+      sla_247
+      allow(instance_with_history).to receive(:escalation_disabled?).and_return(false)
+      result = instance_with_history.send(:escalation_response)
+      expect(result).to be_nil
+    end
+
+    it 'response time is calculated when waiting for the first response with update-only SLA' do
+      sla_247_response.update! first_response_time: nil
+      ticket_with_history.last_contact_customer_at = 2.hours.ago
+      allow(instance_with_history).to receive(:escalation_disabled?).and_return(false)
+      result = instance_with_history.send(:escalation_response)
+      expect(result).to include update_escalation_at: 75.minutes.ago
+    end
+  end
+
+  describe '#escalation_update' do
+    context 'when has open ticket with history' do
+      before do
+        sla_247_update
+        open_ticket_with_history
+        allow(instance_with_open).to receive(:escalation_disabled?).and_return(false)
+      end
+
+      it 'update time is calculated before first agent response' do
+        result = instance_with_open.send(:escalation_update)
+        expect(result).to include update_escalation_at: 50.minutes.from_now
+      end
+
+      it 'update time is calculated after agent response' do
+        create(:ticket_article, :outbound_email, ticket: open_ticket_with_history)
+        result = instance_with_open.send(:escalation_update)
+        expect(result).to include update_escalation_at: 60.minutes.from_now
+      end
+
+      context 'when agent responds' do
+        before do
+          create(:ticket_article, :outbound_email, ticket: open_ticket_with_history)
+          travel 30.minutes
+        end
+
+        it 'update time is calculated after 2nd customer enquiry' do
+          create(:ticket_article, :inbound_email, ticket: open_ticket_with_history)
+          result = instance_with_open.send(:escalation_update)
+          expect(result).to include update_escalation_at: 30.minutes.from_now
+        end
+
+        it 'update time is calculated after 2nd agent response interrupted by customer' do
+          create(:ticket_article, :inbound_email, ticket: open_ticket_with_history)
+          travel 30.minutes
+          create(:ticket_article, :outbound_email, ticket: open_ticket_with_history)
+          result = instance_with_open.send(:escalation_update)
+          expect(result).to include update_escalation_at: 60.minutes.from_now
+        end
+
+        it 'update time is calculated after 2nd agent response in a row' do
+          create(:ticket_article, :outbound_email, ticket: open_ticket_with_history)
+          result = instance_with_open.send(:escalation_update)
+          expect(result).to include update_escalation_at: 60.minutes.from_now
+        end
+      end
+    end
+
+    it 'returns nil when no sla#update_time' do
+      sla_247
+      allow(instance_with_open).to receive(:escalation_disabled?).and_return(false)
+      result = instance_with_open.send(:escalation_update)
+      expect(result).to be_nil
     end
   end
 
@@ -387,16 +478,16 @@ RSpec.describe ::Escalation do
 
   describe '#statistics_first_response' do
     it 'calculates statistics' do
-      sla_247
+      sla_247_response
       ticket_with_history.first_response_at = 45.minutes.ago
       instance_with_history.force!
 
       result = instance_with_history.send(:statistics_first_response)
-      expect(result).to include(first_response_in_min: 75, first_response_diff_in_min: -15)
+      expect(result).to include(first_response_in_min: 75, first_response_diff_in_min: -45)
     end
 
     it 'does not touch statistics when sla time is nil' do
-      sla_247.update! first_response_time: nil
+      sla_247_response.update! first_response_time: nil
       ticket_with_history.first_response_at = 45.minutes.ago
       instance_with_history.force!
 
@@ -405,9 +496,9 @@ RSpec.describe ::Escalation do
     end
   end
 
-  describe '#statistics_update' do
+  describe '#statistics_response' do
     before do
-      sla_247
+      sla_247_response
       freeze_time
     end
 
@@ -415,22 +506,22 @@ RSpec.describe ::Escalation do
       ticket_with_history.last_contact_customer_at = 61.minutes.ago
       ticket_with_history.last_contact_agent_at    = 60.minutes.ago
 
-      result = instance_with_history.send(:statistics_update)
-      expect(result).to include(update_in_min: 1, update_diff_in_min: 59)
+      result = instance_with_history.send(:statistics_response)
+      expect(result).to include(update_in_min: 1, update_diff_in_min: 44)
     end
 
     it 'does not calculate statistics when customer respose is last' do
       ticket_with_history.last_contact_customer_at = 59.minutes.ago
       ticket_with_history.last_contact_agent_at    = 60.minutes.ago
 
-      result = instance_with_history.send(:statistics_update)
+      result = instance_with_history.send(:statistics_response)
       expect(result).to be_nil
     end
 
     it 'does not calculate statistics when only customer enquiry present' do
       create(:ticket_article, :inbound_email, ticket: ticket)
 
-      result = instance.send(:statistics_update)
+      result = instance.send(:statistics_response)
       expect(result).to be_nil
     end
 
@@ -440,7 +531,7 @@ RSpec.describe ::Escalation do
       create(:ticket_article, :outbound_email, ticket: ticket)
 
       instance.force!
-      expect(instance.send(:statistics_update)).to include(update_in_min: 10, update_diff_in_min: 50)
+      expect(instance.send(:statistics_response)).to include(update_in_min: 10, update_diff_in_min: 35)
     end
 
     context 'with multiple exchanges and later one being quicker' do
@@ -455,7 +546,95 @@ RSpec.describe ::Escalation do
       end
 
       it 'keeps statistics of longest exchange' do
-        expect(ticket.reload).to have_attributes(update_in_min: 10, update_diff_in_min: 50)
+        expect(ticket.reload).to have_attributes(update_in_min: 10, update_diff_in_min: 35)
+      end
+    end
+
+    it 'does not touch statistics when sla time is nil' do
+      sla_247.update! update_time: nil
+      ticket_with_history.last_contact_customer_at = 60.minutes.ago
+      instance_with_history.force!
+
+      result = instance_with_history.send(:statistics_update)
+      expect(result).to be_nil
+    end
+
+    it 'does not touch statistics when last update is nil' do
+      ticket_with_history.assign_attributes last_contact_agent_at: nil, last_contact_customer_at: nil
+      instance_with_history.force!
+
+      result = instance_with_history.send(:statistics_update)
+      expect(result).to be_nil
+    end
+  end
+
+  describe '#statistics_update' do
+    before do
+      sla_247_update
+      freeze_time
+    end
+
+    it 'does not calculate statistics when only customer enquiry present' do
+      create(:ticket_article, :inbound_email, ticket: ticket)
+
+      result = instance.send(:statistics_update)
+      expect(result).to be_nil
+    end
+
+    context 'when agent responds after 20 minutes' do
+      before do
+        ticket
+        travel 20.minutes
+        create(:ticket_article, :outbound_email, ticket: ticket)
+      end
+
+      it 'does not touch statistics when customer response is most recent' do
+        travel 30.minutes
+        create(:ticket_article, :inbound_email, ticket: ticket)
+
+        result = instance.send(:statistics_update)
+        expect(result).to include(update_diff_in_min: 40, update_in_min: 20)
+      end
+
+      it 'calculates statistics when only agent update present' do
+        result = instance.send(:statistics_update)
+        expect(result).to include(update_diff_in_min: 40, update_in_min: 20)
+      end
+
+      it 'calculates statistics when multiple agent updates present' do
+        travel 30.minutes
+        create(:ticket_article, :outbound_email, ticket: ticket)
+
+        result = instance.send(:statistics_update)
+        expect(result).to include(update_diff_in_min: 30, update_in_min: 30)
+      end
+
+      context 'when customer responds' do
+        before do
+          travel 10.minutes
+          create(:ticket_article, :inbound_email, ticket: ticket)
+        end
+
+        it 'calculates statistics when multiple agent updates intercepted by customer' do
+          travel 35.minutes
+          create(:ticket_article, :outbound_email, ticket: ticket)
+
+          result = instance.send(:statistics_update)
+          expect(result).to include(update_diff_in_min: 15, update_in_min: 45)
+        end
+      end
+    end
+
+    context 'with multiple exchanges and later one being quicker' do
+      before do
+        travel 10.minutes
+        create(:ticket_article, :outbound_email, ticket: ticket)
+        travel 5.minutes
+        create(:ticket_article, :outbound_email, ticket: ticket)
+      end
+
+      it 'keeps statistics of longest exchange' do
+        expect(ticket.reload).to have_attributes(update_in_min: 5, update_diff_in_min: 55)
       end
     end
 
@@ -512,7 +691,7 @@ RSpec.describe ::Escalation do
   it 'switching state pushes escalation date' do
     sla_247
     open_ticket_with_history.reload
-    expect(open_ticket_with_history.update_escalation_at).to eq open_ticket_with_history.created_at + 70.minutes
+    expect(open_ticket_with_history.escalation_at).to eq open_ticket_with_history.created_at + 85.minutes
   end
 
   def without_update_escalation_information_callback(&block)
diff --git a/spec/models/calendar_spec.rb b/spec/models/calendar_spec.rb
index f2f66cab8..4be059ef4 100644
--- a/spec/models/calendar_spec.rb
+++ b/spec/models/calendar_spec.rb
@@ -303,7 +303,7 @@ RSpec.describe Calendar, type: :model do
              })
     end
 
-    let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 60, update_time: 120, solution_time: nil) }
+    let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 60, response_time: 120, solution_time: nil) }
 
     before do
       queue_adapter.perform_enqueued_jobs = true
@@ -400,7 +400,7 @@ RSpec.describe Calendar, type: :model do
              calendar:            calendar,
              condition:           {},
              first_response_time: 120,
-             update_time:         180,
+             response_time:       180,
              solution_time:       240)
     end
 
diff --git a/spec/models/core_workflow_spec.rb b/spec/models/core_workflow_spec.rb
index 711f582a0..065bb5c7c 100644
--- a/spec/models/core_workflow_spec.rb
+++ b/spec/models/core_workflow_spec.rb
@@ -377,7 +377,7 @@ RSpec.describe CoreWorkflow, type: :model do
         base_payload.merge(
           'screen'     => 'edit',
           'class_name' => 'Sla',
-          'params'     => { 'update_time_enabled' => 'true' }
+          'params'     => { 'update_time_enabled' => 'true', 'update_type' => 'update' }
         )
       end
 
diff --git a/spec/models/sla/has_escalation_calculation_impact_examples.rb b/spec/models/sla/has_escalation_calculation_impact_examples.rb
index 4f390b6c1..de8b222ce 100644
--- a/spec/models/sla/has_escalation_calculation_impact_examples.rb
+++ b/spec/models/sla/has_escalation_calculation_impact_examples.rb
@@ -11,7 +11,7 @@ RSpec.shared_examples 'HasEscalationCalculationImpact', :performs_jobs do
 
   context 'when affected Ticket existed' do
 
-    subject(:sla) { create(:sla, calendar: calendar, first_response_time: 60, update_time: 180, solution_time: 240) }
+    subject(:sla) { create(:sla, calendar: calendar, first_response_time: 60, response_time: 180, solution_time: 240) }
 
     let(:calendar) { create(:calendar, :business_hours_9_17) }
     let!(:ticket) { create(:ticket) }
@@ -78,7 +78,7 @@ RSpec.shared_examples 'HasEscalationCalculationImpact', :performs_jobs do
                  },
                },
                first_response_time: 10,
-               update_time:         20,
+               response_time:       20,
                solution_time:       300)
       end
 
@@ -92,7 +92,7 @@ RSpec.shared_examples 'HasEscalationCalculationImpact', :performs_jobs do
                  },
                },
                first_response_time: 120,
-               update_time:         180,
+               response_time:       180,
                solution_time:       240)
       end
 
@@ -130,7 +130,7 @@ RSpec.shared_examples 'HasEscalationCalculationImpact', :performs_jobs do
                },
                calendar:            calendar,
                first_response_time: 60,
-               update_time:         120,
+               response_time:       120,
                solution_time:       180)
       end
 
@@ -172,7 +172,7 @@ RSpec.shared_examples 'HasEscalationCalculationImpact', :performs_jobs do
                },
                calendar:            calendar,
                first_response_time: 60,
-               update_time:         120,
+               response_time:       120,
                solution_time:       180)
       end
 
@@ -214,7 +214,7 @@ RSpec.shared_examples 'HasEscalationCalculationImpact', :performs_jobs do
                },
                calendar:            calendar,
                first_response_time: 60,
-               update_time:         120,
+               response_time:       120,
                solution_time:       180)
       end
 
diff --git a/spec/models/sla_spec.rb b/spec/models/sla_spec.rb
index 8b9d1dbe0..005d4006d 100644
--- a/spec/models/sla_spec.rb
+++ b/spec/models/sla_spec.rb
@@ -35,6 +35,28 @@ RSpec.describe Sla, type: :model do
       end
     end
 
+    describe '#cannot_have_response_and_update' do
+      it 'allows neither #response_time nor #update_time' do
+        instance = build(:sla, response_time: nil, update_time: nil)
+        expect(instance).to be_valid
+      end
+
+      it 'allows #response_time' do
+        instance = build(:sla, response_time: 180, update_time: nil)
+        expect(instance).to be_valid
+      end
+
+      it 'allows #update_time' do
+        instance = build(:sla, response_time: nil, update_time: 180)
+        expect(instance).to be_valid
+      end
+
+      it 'denies both #response_time and #update_time' do
+        instance = build(:sla, response_time: 180, update_time: 180)
+        expect(instance).not_to be_valid
+      end
+    end
+
     describe '.for_ticket' do
       it 'returns matching SLA for the ticket' do
         sla
diff --git a/spec/models/ticket/article/has_ticket_contact_attributes_impact_examples.rb b/spec/models/ticket/article/has_ticket_contact_attributes_impact_examples.rb
index 5d80c3fdd..7ae7f0f59 100644
--- a/spec/models/ticket/article/has_ticket_contact_attributes_impact_examples.rb
+++ b/spec/models/ticket/article/has_ticket_contact_attributes_impact_examples.rb
@@ -39,7 +39,7 @@ RSpec.shared_examples 'Ticket::Article::HasTicketContactAttributesImpact' do
                },
              })
     end
-    let(:sla) { create(:sla, calendar: calendar, first_response_time: 60, update_time: 120, solution_time: 180) }
+    let(:sla) { create(:sla, calendar: calendar, first_response_time: 60, response_time: 120, solution_time: 180) }
 
     before do
       sla
@@ -174,7 +174,7 @@ RSpec.shared_examples 'Ticket::Article::HasTicketContactAttributesImpact' do
                })
       end
 
-      let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 60, update_time: 120, solution_time: nil) }
+      let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 60, response_time: 120, solution_time: nil) }
 
       before do
         sla
@@ -252,7 +252,7 @@ RSpec.shared_examples 'Ticket::Article::HasTicketContactAttributesImpact' do
                })
       end
 
-      let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 60, update_time: 120, solution_time: nil) }
+      let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 60, response_time: 120, solution_time: nil) }
 
       before do
         Setting.set('ticket_last_contact_behaviour', 'based_on_customer_reaction')
diff --git a/spec/models/ticket/escalation_examples.rb b/spec/models/ticket/escalation_examples.rb
index a1bd2388e..c74d5ff96 100644
--- a/spec/models/ticket/escalation_examples.rb
+++ b/spec/models/ticket/escalation_examples.rb
@@ -41,7 +41,7 @@ RSpec.shared_examples 'Ticket::Escalation' do
                  },
                })
       end
-      let(:sla) { create(:sla, calendar: calendar, first_response_time: 60, update_time: 120, solution_time: 180) }
+      let(:sla) { create(:sla, calendar: calendar, first_response_time: 60, response_time: 120, solution_time: 180) }
       let(:article) { create(:'ticket/article', :inbound_email, ticket: ticket, created_at: '2013-03-21 09:30:00 UTC', updated_at: '2013-03-21 09:30:00 UTC') }
 
       before do
@@ -434,7 +434,7 @@ RSpec.shared_examples 'Ticket::Escalation' do
                  },
                },
                first_response_time: 60,
-               update_time:         180,
+               response_time:       180,
                solution_time:       240)
       end
 
@@ -512,7 +512,7 @@ RSpec.shared_examples 'Ticket::Escalation' do
                })
       end
 
-      let(:sla) { create(:sla, calendar: calendar, first_response_time: 120, update_time: 180, solution_time: 250) }
+      let(:sla) { create(:sla, calendar: calendar, first_response_time: 120, response_time: 180, solution_time: 250) }
 
       context 'when Ticket is reopened' do
 
@@ -663,7 +663,7 @@ RSpec.shared_examples 'Ticket::Escalation' do
                  })
         end
 
-        let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 120, update_time: 180, solution_time: 250) }
+        let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 120, response_time: 180, solution_time: 250) }
 
         before do
           sla
@@ -774,7 +774,7 @@ RSpec.shared_examples 'Ticket::Escalation' do
                  })
         end
 
-        let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 120, update_time: 180, solution_time: 240) }
+        let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 120, response_time: 180, solution_time: 240) }
 
         before do
           sla
@@ -851,7 +851,7 @@ RSpec.shared_examples 'Ticket::Escalation' do
                  })
         end
 
-        let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 120, update_time: 180, solution_time: 240) }
+        let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 120, response_time: 180, solution_time: 240) }
 
         before do
           sla
@@ -950,7 +950,7 @@ RSpec.shared_examples 'Ticket::Escalation' do
                  })
         end
 
-        let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 120, update_time: 180, solution_time: 240) }
+        let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 120, response_time: 180, solution_time: 240) }
 
         before do
           sla
@@ -1068,7 +1068,7 @@ RSpec.shared_examples 'Ticket::Escalation' do
                })
       end
 
-      let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 120, update_time: 1200, solution_time: nil) }
+      let(:sla) { create(:sla, condition: {}, calendar: calendar, first_response_time: 120, response_time: 1200, solution_time: nil) }
 
       before do
         sla
diff --git a/spec/models/ticket_spec.rb b/spec/models/ticket_spec.rb
index 748e18849..c3696d7f0 100644
--- a/spec/models/ticket_spec.rb
+++ b/spec/models/ticket_spec.rb
@@ -1167,7 +1167,7 @@ RSpec.describe Ticket, type: :model do
     describe '#escalation_at' do
       before { travel_to(Time.current) } # freeze time
 
-      let(:sla) { create(:sla, calendar: calendar, first_response_time: 60, update_time: 180, solution_time: 240) }
+      let(:sla) { create(:sla, calendar: calendar, first_response_time: 60, response_time: 180, solution_time: 240) }
       let(:calendar) { create(:calendar, :'24/7') }
 
       context 'with no SLAs in the system' do
@@ -1378,7 +1378,7 @@ RSpec.describe Ticket, type: :model do
     describe '#first_response_escalation_at' do
       before { travel_to(Time.current) } # freeze time
 
-      let(:sla) { create(:sla, calendar: calendar, first_response_time: 60, update_time: 180, solution_time: 240) }
+      let(:sla) { create(:sla, calendar: calendar, first_response_time: 60, response_time: 180, solution_time: 240) }
       let(:calendar) { create(:calendar, :'24/7') }
 
       context 'with no SLAs in the system' do
@@ -1410,7 +1410,7 @@ RSpec.describe Ticket, type: :model do
     describe '#update_escalation_at' do
       before { travel_to(Time.current) } # freeze time
 
-      let(:sla) { create(:sla, calendar: calendar, first_response_time: 60, update_time: 180, solution_time: 240) }
+      let(:sla) { create(:sla, calendar: calendar, first_response_time: 60, response_time: 180, solution_time: 240) }
       let(:calendar) { create(:calendar, :'24/7') }
 
       context 'with no SLAs in the system' do
@@ -1450,7 +1450,7 @@ RSpec.describe Ticket, type: :model do
     describe '#close_escalation_at' do
       before { travel_to(Time.current) } # freeze time
 
-      let(:sla) { create(:sla, calendar: calendar, first_response_time: 60, update_time: 180, solution_time: 240) }
+      let(:sla) { create(:sla, calendar: calendar, first_response_time: 60, response_time: 180, solution_time: 240) }
       let(:calendar) { create(:calendar, :'24/7') }
 
       context 'with no SLAs in the system' do
diff --git a/spec/requests/ticket/escalation_spec.rb b/spec/requests/ticket/escalation_spec.rb
index da71adec5..a5866bc2c 100644
--- a/spec/requests/ticket/escalation_spec.rb
+++ b/spec/requests/ticket/escalation_spec.rb
@@ -4,8 +4,8 @@ require 'rails_helper'
 
 RSpec.describe 'Ticket Escalation', type: :request do
   let(:sla_first_response) { 1.hour }
-  let(:sla_update)         { 3.hours }
-  let(:sla_close)          { 4.hours }
+  let(:sla_response)         { 3.hours }
+  let(:sla_close) { 4.hours }
 
   let!(:mail_group) { create(:group, email_address: create(:email_address)) }
 
@@ -14,7 +14,7 @@ RSpec.describe 'Ticket Escalation', type: :request do
     create(:sla,
            calendar:            calendar,
            first_response_time: sla_first_response / 1.minute,
-           update_time:         sla_update / 1.minute,
+           response_time:       sla_response / 1.minute,
            solution_time:       sla_close / 1.minute)
   end
 
diff --git a/spec/system/manage/sla_spec.rb b/spec/system/manage/sla_spec.rb
index 385109e81..50945c1d5 100644
--- a/spec/system/manage/sla_spec.rb
+++ b/spec/system/manage/sla_spec.rb
@@ -14,6 +14,7 @@ RSpec.describe 'Manage > Sla', type: :system do
 
     # enable all checkboxes
     page.find('input#update_time', visible: false).find(:xpath, './/..').click
+    page.first('.js-updateTypeSelector', visible: false).click
     page.find('input#solution_time', visible: false).find(:xpath, './/..').click
 
     # check if required