diff --git a/src/components/workflows/WorkflowsTable.vue b/src/components/workflows/WorkflowsTable.vue
index f42c6f2..56ec905 100644
--- a/src/components/workflows/WorkflowsTable.vue
+++ b/src/components/workflows/WorkflowsTable.vue
@@ -2,19 +2,29 @@
 import { watch, ref, onMounted, computed } from "vue"
 import { useI18n } from "vue-i18n"
 import { createReadableMetricValue, getEvalColor, mapGtId } from "@/helpers/utils"
-import type { EvaluationRun } from "@/types"
+import type { EvalDefinitions, EvaluationResultsDocumentWide, EvaluationRun, GroupedTableData } from "@/types"
 import Dropdown from 'primevue/dropdown'
+import Checkbox from 'primevue/checkbox'
 import workflowsStore from "@/store/workflows-store"
 import api from "@/helpers/api"
 import filtersStore from "@/store/filters-store"
 import TrendLegend from "@/components/workflows/TrendLegend.vue"
+import WorkflowsTableSorter from "@/components/workflows/timeline/WorkflowTableSorter.vue"
 
 const { t } = useI18n()
 
-const groupedData = ref({})
-const evals = ref([])
+const groupedData = ref<GroupedTableData>({})
+const sortedData = ref<GroupedTableData>({})
+const evals = ref<string[]>([])
+const sortBy = ref<keyof EvaluationResultsDocumentWide | null>(null)
 
-const sortOptions = ref([{
+const tableData = computed<GroupedTableData>(() => {
+  return (sortBy.value === null || Object.keys(sortedData.value).length === 0) ? groupedData.value : sortedData.value
+})
+
+const keepGroupsWhenSorting = ref(true)
+
+const groupingOptions = ref([{
   value: 'documents',
   label: t('documents')
 }, {
@@ -22,10 +32,10 @@ const sortOptions = ref([{
   label: t('workflows')
 }])
 
-const sortBy = ref(sortOptions.value[0])
+const groupBy = ref(groupingOptions.value[0])
 const latestRuns = ref<EvaluationRun[]>([])
 const filteredRuns = ref<EvaluationRun[]>([])
-const evalDefinitions = ref([])
+const evalDefinitions = ref<EvalDefinitions>({})
 const loading = ref(false)
 
 onMounted(async () => {
@@ -33,17 +43,17 @@ onMounted(async () => {
   latestRuns.value = workflowsStore.getLatestRuns()
   evalDefinitions.value = await api.getEvalDefinitions()
   setFilteredRuns()
-  groupRuns(sortBy.value.value)
+  groupRuns(groupBy.value.value)
   loading.value = false
 })
 
 watch(() => filtersStore.gt, () => {
   setFilteredRuns()
-  groupRuns(sortBy.value.value)
+  groupRuns(groupBy.value.value)
 })
 
-watch(sortBy, () => {
-  groupRuns(sortBy.value.value)
+watch(groupBy, () => {
+  groupRuns(groupBy.value.value)
 })
 
 function setFilteredRuns() {
@@ -53,6 +63,7 @@ function setFilteredRuns() {
 function groupRuns(groupBy: string) {
   if (groupBy === 'workflows') groupByWorkflows()
   else if (groupBy === 'documents') groupByDocuments()
+  sortBy.value = null
 }
 
 const groupByWorkflows = () => {
@@ -66,7 +77,7 @@ const groupByWorkflows = () => {
       label: workflowsStore.getGtById(mapGtId(cur.metadata.gt_workspace.id))?.label,
       evaluations: Object.keys(cur.evaluation_results.document_wide).map(key => ({
         name: key,
-        value: cur.evaluation_results.document_wide[key]
+        value: cur.evaluation_results.document_wide[key as keyof EvaluationResultsDocumentWide]
       }))
     }
     if (!acc[ocrWorkflowId]) {
@@ -77,12 +88,12 @@ const groupByWorkflows = () => {
     } else {
       acc[ocrWorkflowId].subjects.push(subject)
       acc[ocrWorkflowId].subjects.sort((a, b) => {
-        if (a.label > b.label) return 1
+        if ((a.label && b.label) && a.label > b.label) return 1
         else return -1
       })
     }
     return acc
-  }, {})
+  }, {} as GroupedTableData)
 }
 
 const groupByDocuments = () => {
@@ -94,7 +105,7 @@ const groupByDocuments = () => {
       label: workflowsStore.getWorkflowById(mapGtId(cur.metadata.ocr_workflow['id']))?.label,
       evaluations: Object.keys(cur.evaluation_results.document_wide).map(key => ({
         name: key,
-        value: cur.evaluation_results.document_wide[key]
+        value: cur.evaluation_results.document_wide[key as keyof EvaluationResultsDocumentWide]
       }))
     }
     if (!acc[gtWorkspaceId]) {
@@ -105,12 +116,21 @@ const groupByDocuments = () => {
     } else {
       acc[gtWorkspaceId].subjects.push(subject)
       acc[gtWorkspaceId].subjects.sort((a, b) => {
-        if (a.label > b.label) return 1
+        if ((a.label && b.label) && a.label > b.label) return 1
         else return -1
       })
     }
     return acc
-  }, {})
+  }, {} as GroupedTableData)
+}
+
+const getSortValue = (key: keyof EvaluationResultsDocumentWide) => {
+  return sortBy.value === key
+}
+
+const setSorted = (event: GroupedTableData, key: keyof EvaluationResultsDocumentWide) => {
+  sortBy.value = key
+  sortedData.value = event
 }
 </script>
 
@@ -119,21 +139,33 @@ const groupByDocuments = () => {
     Loading...
   </template>
   <template v-else>
-    <div class="flex flex-col" v-if="Object.keys(groupedData).length > 0">
+    <div class="flex flex-col" v-if="Object.keys(tableData).length > 0">
       <div class="flex items-center mb-4 ml-auto">
+        <label for="keepGroupsCheckbox" class="mr-2">{{ $t('keep_grouping_when_sorting') }}</label>
+        <Checkbox v-model="keepGroupsWhenSorting" input-id="keepGroupsCheckbox" binary class="mr-8"></Checkbox>
+        
         <p class="mr-2">{{ $t('group_by') }}:</p>
-        <Dropdown v-model="sortBy" :options="sortOptions" optionLabel="label" placeholder="Choose something.." class="" />
+        <Dropdown v-model="groupBy" :options="groupingOptions" optionLabel="label" placeholder="Choose something.." class="" />
       </div>
       <TrendLegend :show-text-colors="false" class="ml-auto mb-4"/>
     </div>
-    <table v-if="Object.keys(groupedData).length > 0" class="w-full border border-collapse rounded text-sm">
+    <table v-if="Object.keys(tableData).length > 0" class="w-full border border-collapse rounded text-sm">
       <thead>
       <tr>
-        <th class="p-2 border">{{ sortBy.value === 'documents' ? $t('documents') : $t('workflows') }}</th>
-        <th class="p-2 border">{{ sortBy.value === 'documents' ? $t('workflows') : $t('documents') }}</th>
+        <th class="p-2 border">{{ groupBy.value === 'documents' ? $t('documents') : $t('workflows') }}</th>
+        <th class="p-2 border">{{ groupBy.value === 'documents' ? $t('workflows') : $t('documents') }}</th>
         <th v-for="(evalKey, i) in evals" :key="i" class="p-2 border">
           <span class="def-label flex items-center justify-center cursor-pointer">
-            {{ evalDefinitions[evalKey] ? evalDefinitions[evalKey].label : evalKey }}
+            <WorkflowsTableSorter 
+              :grouped-data="groupedData" 
+              :metric="(evalKey as keyof EvaluationResultsDocumentWide)" 
+              :sort="getSortValue(evalKey as keyof EvaluationResultsDocumentWide)"
+              :keep-grouping="keepGroupsWhenSorting"
+              @sorted-data="setSorted($event, evalKey as keyof EvaluationResultsDocumentWide)"
+              @unsorted-data="sortBy = null"
+            >
+              {{ evalDefinitions[evalKey] ? evalDefinitions[evalKey].label : evalKey }}
+            </WorkflowsTableSorter>
             <i-icon name="ink-info"/>
             <div class="def-tooltip">
               <div class="flex p-2 bg-white border rounded">
@@ -146,22 +178,22 @@ const groupByDocuments = () => {
       </tr>
       </thead>
       <tbody>
-      <template v-for="(key, i) in Object.keys(groupedData)" :key="i">
-        <tr v-for="(subject, j) in groupedData[key].subjects" :key="j">
-          <td v-if="j === 0" :rowspan="groupedData[key].subjects.length" class="align-top pl-2 border w-1/3">
-            <span class="font-bold">{{ groupedData[key].label }}</span>
+      <template v-for="(key, i) in Object.keys(tableData)" :key="i">
+        <tr v-for="(subject, j) in tableData[key].subjects" :key="j">
+          <td v-if="j === 0" :rowspan="tableData[key].subjects.length" class="align-top pl-2 border w-1/3">
+            <span class="font-bold">{{ tableData[key].label }}</span>
           </td>
           <td class="align-top pl-2 border">{{ subject.label }}</td>
           <td
             v-for="({ name, value }, k) in subject.evaluations"
             :key="k"
             class="text-center pt-1 border"
-            :class="(j === groupedData[key].subjects.length - 1) ? 'pb-5' : 'pb-1'"
+            :class="(j === tableData[key].subjects.length - 1) ? 'pb-5' : 'pb-1'"
           >
             <span
               class="metric inline-block cursor-pointer text-sm leading-none p-1 rounded-lg min-w-[48px]"
               :class="getEvalColor(name, value)">
-              {{ createReadableMetricValue(name, value) }}
+              {{ createReadableMetricValue(name as keyof EvaluationResultsDocumentWide, value) }}
             </span>
           </td>
         </tr>
diff --git a/src/components/workflows/timeline/WorkflowTableSorter.vue b/src/components/workflows/timeline/WorkflowTableSorter.vue
new file mode 100644
index 0000000..012ffb4
--- /dev/null
+++ b/src/components/workflows/timeline/WorkflowTableSorter.vue
@@ -0,0 +1,120 @@
+<script setup lang="ts">
+import Button from "primevue/button"
+import { Icon } from "@iconify/vue"
+import { ref, watch } from "vue"
+import type { GroupedTableData, EvaluationResultsDocumentWide, GroupedTableDataSubject } from "@/types"
+const props = withDefaults(
+  defineProps<{
+    groupedData: GroupedTableData
+    metric: keyof EvaluationResultsDocumentWide
+    sort?: boolean
+    keepGrouping?: boolean
+  }>(), 
+  {
+    sort: false,
+    keepGrouping: true
+  }
+)
+const emit = defineEmits<{
+  (event: 'sortedData', payload: GroupedTableData): void,
+  (event: 'unsortedData'): void
+}>()
+
+type GroupedEntry = [string, GroupedTableData[keyof GroupedTableData]]
+
+enum sortStates {
+  none,
+  desc,
+  asc,
+  __LENGTH
+}
+const sortState = ref(sortStates.none)
+
+//set sortState to none if sort changes to false to enable sorting by only a single column at a time 
+watch(() => props.sort, () => {
+  if(!props.sort) sortState.value = sortStates.none
+}) 
+
+watch(() => props.keepGrouping, () => {
+  if(sortState.value !== sortStates.none) sort()
+})
+
+const cycleAndSort = () => {
+  cycleSortState()
+  sort()
+}
+
+const cycleSortState = () => {
+  sortState.value = (sortState.value + 1) % sortStates.__LENGTH
+}
+
+const sort = () => {
+  if (sortState.value === sortStates.none) {
+    emit('unsortedData')
+    return
+  }
+  const groupedEntries = Object.entries(props.groupedData)
+  const entries = props.keepGrouping ? groupedEntries : transformToSingleSubjectGrouping(groupedEntries)
+  const entriesWithSortedSubjects = entries.map(elem => {
+    const sorted: typeof elem[1] = { label: elem[1].label, subjects: sortSubjects(elem[1].subjects, sortState.value === sortStates.desc) }
+    return [elem[0], sorted]
+  })
+  const sortedData: GroupedTableData = Object.fromEntries(
+    entriesWithSortedSubjects
+    .sort((left, right) => {
+      const leftData = left[1] as GroupedTableData[keyof GroupedTableData]
+      const rightData = right[1] as GroupedTableData[keyof GroupedTableData]
+
+      const compareByFirstSubject = (subjectsLeft: GroupedTableDataSubject[], subjectsRight: GroupedTableDataSubject[]) => {
+        return compareSubjects(subjectsLeft[0], subjectsRight[0])
+      }
+
+      return sortState.value === sortStates.desc ? 
+        compareByFirstSubject(rightData.subjects, leftData.subjects) 
+      : compareByFirstSubject(leftData.subjects, rightData.subjects) 
+    })
+  )
+  emit('sortedData', sortedData)
+}
+
+const sortSubjects = (subjects: GroupedTableDataSubject[], desc: boolean) => {
+  return [...subjects] //copy to avoid sorting in place
+  .sort((left: GroupedTableDataSubject, right: GroupedTableDataSubject) => {
+    return desc ? compareSubjects(right, left) : compareSubjects(left, right)
+  })
+}
+
+const compareSubjects = (left: GroupedTableDataSubject, right: GroupedTableDataSubject) => {
+  const transformValue = (value: number | number [] | null | undefined): number => {
+    const definedValue = value ?? 0
+    return Array.isArray(definedValue) ? definedValue[0] : definedValue
+  }
+  const evaluationLeft = left.evaluations.find(elem => props.metric === elem.name)
+  const evaluationRight = right.evaluations.find(elem => props.metric === elem.name)
+  const valueLeft = transformValue(evaluationLeft?.value)
+  const valueRight = transformValue(evaluationRight?.value)
+  return valueLeft - valueRight
+}
+
+const transformToSingleSubjectGrouping = (groupedEntries: GroupedEntry[]): GroupedEntry[] => {
+  return groupedEntries.reduce((acc, curr) => {
+    curr[1].subjects.forEach((subject, index) => {
+      acc.push([`${curr[0]}_${index}`, { label: curr[1].label, subjects: [subject] }])
+    })
+    return acc
+  }, [] as GroupedEntry[])
+}
+
+</script>
+<template>
+  <Button @click="cycleAndSort()" unstyled>
+    <div class="flex items-center space-x-2">
+      <slot/>
+      <span class="flex h-6 w-6 justify-center items-center">
+        <Icon v-if="sortState === sortStates.desc" icon="typcn:arrow-sorted-down"/>
+        <Icon v-else-if="sortState === sortStates.asc" icon="typcn:arrow-sorted-up"/>
+        <Icon v-else icon="typcn:arrow-unsorted"></Icon>
+      </span>
+    </div>
+  </Button>
+</template>
\ No newline at end of file
diff --git a/src/helpers/api.ts b/src/helpers/api.ts
index dccf74c..f44b999 100644
--- a/src/helpers/api.ts
+++ b/src/helpers/api.ts
@@ -1,4 +1,4 @@
-import type { EvaluationRun, GroundTruth, Workflow } from "@/types"
+import type { EvalDefinitions, EvaluationRun, GroundTruth, Workflow } from "@/types"
 
 const baseUrlOld = 'https://raw.githubusercontent.com/OCR-D/quiver-back-end/main/data'
 const baseUrl = 'https://quiver-dev.sub.uni-goettingen.de/api'
@@ -10,7 +10,7 @@ async function getOcrdAllReleases() {
     return await request(baseUrlOld + '/ocrd_all_releases.json')
 }
 
-async function getEvalDefinitions() {
+async function getEvalDefinitions(): Promise<EvalDefinitions> {
     return await request(baseUrlOld + '/metrics_definitions.json')
 }
 
diff --git a/src/locales/de.json b/src/locales/de.json
index db55ba1..c623530 100644
--- a/src/locales/de.json
+++ b/src/locales/de.json
@@ -86,5 +86,6 @@
   "filter_by_processor": "Nach Prozessor filtern",
   "select_a_date_range": "Zeitraum auswählen",
   "select_a_workflow": "Workflow auswählen",
-  "select_a_processor": "Prozessor auswählen"
+  "select_a_processor": "Prozessor auswählen",
+  "keep_grouping_when_sorting": "Gruppierung beim Sortieren beibehalten"
 }
diff --git a/src/locales/en.json b/src/locales/en.json
index 2fc3f36..712ccc1 100644
--- a/src/locales/en.json
+++ b/src/locales/en.json
@@ -80,5 +80,6 @@
   "filter_by_processor": "Filter by processor",
   "select_a_date_range": "Select a date range",
   "select_a_workflow": "Select a workflow",
-  "select_a_processor": "Select a processor"
+  "select_a_processor": "Select a processor",
+  "keep_grouping_when_sorting": "Keep grouping when sorting"
 }
diff --git a/src/types/index.d.ts b/src/types/index.d.ts
index 2776794..0261ddb 100644
--- a/src/types/index.d.ts
+++ b/src/types/index.d.ts
@@ -141,3 +141,26 @@ export interface ReleaseInfo {
   html_url: string
 }
 
+export interface EvalDefinitions {
+  [id: string]: {
+    label: string,
+    short_descr: string,
+    url: string 
+  }
+}
+
+export interface GroupedTableData {
+  [gtWorkId: string]: {
+    label: string | undefined,
+    subjects: GroupedTableDataSubject[]
+  }
+}
+
+
+export interface GroupedTableDataSubject {
+  label: string | undefined
+  evaluations: {
+    name: string
+    value: number | number[] | null
+  }[]
+}