diff --git a/src/modules/feature/FeatureSteps.vue b/src/modules/feature/FeatureSteps.vue
index 6a814c5..c015987 100644
--- a/src/modules/feature/FeatureSteps.vue
+++ b/src/modules/feature/FeatureSteps.vue
@@ -7,6 +7,14 @@ import { onMounted } from 'vue'
 const featureStore = useFeatureStore()
 
 onMounted(() => featureStore.initBoard())
+
+const problemSolving20Percent = () => {
+  if (featureStore.meta.totalDays % 5 === 0) {
+    featureStore.nextDay('problem-solving')
+  } else {
+    featureStore.nextDay('pull')
+  }
+}
 </script>
 
 <template>
@@ -19,8 +27,9 @@ onMounted(() => featureStore.initBoard())
     <div>
       <button @click="featureStore.nextDay('push')">push system</button>
       <button @click="featureStore.nextDay('pull')">pull system</button>
-      <button @click="featureStore.nextDay('turn-off')">
-        next day without new feature
+      <button @click="problemSolving20Percent">pull and problem solving</button>
+      <button @click="featureStore.nextDay('problem-solving')">
+        problem solving
       </button>
       Total days: {{ featureStore.meta.totalDays }}
     </div>
diff --git a/src/modules/feature/feature-board.ts b/src/modules/feature/feature-board.ts
index 0402bba..c0b92dd 100644
--- a/src/modules/feature/feature-board.ts
+++ b/src/modules/feature/feature-board.ts
@@ -6,34 +6,39 @@ import { pickRandomElement, popNElement, shuffleArray } from '@/utils'
 
 const MAX_FEATURES = 30
 
-const hasQualityIssue = (
-  complexity: number,
+const hasQualityIssue = ({
+  complexity,
+  tasksInParallel,
+  daysWithProblemSolving
+}: {
+  complexity: number
   tasksInParallel: number
-): boolean => {
-  let probabilityOfQualityIssue = 0
+  daysWithProblemSolving: number
+}): boolean => {
+  let probabilityOfGoodQuality = 1
 
   switch (complexity) {
     case 1:
-      probabilityOfQualityIssue = 0.97
+      probabilityOfGoodQuality = 0.97
 
     case 2:
-      probabilityOfQualityIssue = 0.93
+      probabilityOfGoodQuality = 0.93
       break
     case 3:
-      probabilityOfQualityIssue = 0.88
+      probabilityOfGoodQuality = 0.88
       break
     case 4:
-      probabilityOfQualityIssue = 0.82
+      probabilityOfGoodQuality = 0.82
       break
     case 5:
-      probabilityOfQualityIssue = 0.75
-      break
-
-    default:
-      probabilityOfQualityIssue = 0.65
+      probabilityOfGoodQuality = 0.75
       break
   }
 
+  // learnings
+  probabilityOfGoodQuality =
+    probabilityOfGoodQuality + (1.2 * daysWithProblemSolving) / 100
+
   let multiplicator = 1
 
   switch (tasksInParallel) {
@@ -47,11 +52,13 @@ const hasQualityIssue = (
       multiplicator = 1.1
     case 5:
       multiplicator = 1.15
-    default:
+    case 6:
       multiplicator = 1.25
+    default:
+      multiplicator = 1.4
   }
 
-  return Math.random() > probabilityOfQualityIssue / multiplicator
+  return Math.random() > probabilityOfGoodQuality / multiplicator
 }
 
 export const newBoard = () => shuffleArray(features)
@@ -76,13 +83,15 @@ export const nextDay = ({
   features,
   initialStep,
   steps,
-  strategy
+  strategy,
+  daysWithProblemSolving
 }: {
   backlog: Feature[]
   features: Feature[]
   steps: FeatureStep[]
   initialStep: number
   strategy: Strategy
+  daysWithProblemSolving: number
 }): Feature[] => {
   features.forEach((feature) => {
     const isFeatureLive = feature.step === 0 && feature.status === 'done'
@@ -120,12 +129,13 @@ export const nextDay = ({
         }
 
         if (
-          hasQualityIssue(
-            feature.complexity,
-            features.filter(
+          hasQualityIssue({
+            complexity: feature.complexity,
+            tasksInParallel: features.filter(
               (f) => f.status === 'doing' && f.step === feature.step
-            ).length
-          )
+            ).length,
+            daysWithProblemSolving
+          })
         ) {
           feature.step = Math.min(4, feature.step + 1)
           feature.qualityIssue++
@@ -167,8 +177,6 @@ export const nextDay = ({
           }
         }
       }
-      case 'turn-off':
-        break
     }
   }
 
diff --git a/src/modules/feature/store.ts b/src/modules/feature/store.ts
index 86008e8..1d9028c 100644
--- a/src/modules/feature/store.ts
+++ b/src/modules/feature/store.ts
@@ -11,16 +11,18 @@ type State = {
   backlog: Feature[]
   meta: {
     totalDays: number
+    daysWithProblemSolving: number
     strategy: Record<Strategy, number>
   }
 }
 
 const resetMeta = (): State['meta'] => ({
   totalDays: 0,
+  daysWithProblemSolving: 0,
   strategy: {
     push: 0,
     pull: 0,
-    'turn-off': 0
+    'problem-solving': 0
   }
 })
 
@@ -39,15 +41,22 @@ export const useFeatureStore = defineStore('feature', {
       this.meta = resetMeta()
     },
     nextDay(strategy: Strategy) {
+      this.meta.totalDays++
+      this.meta.strategy[strategy]++
+
+      if (strategy === 'problem-solving') {
+        this.meta.daysWithProblemSolving++
+        return
+      }
+
       this.features = nextDay({
         backlog: this.backlog,
         features: this.features,
         steps: this.steps,
         initialStep: this.steps[0].stepIndex,
-        strategy
+        strategy,
+        daysWithProblemSolving: this.meta.daysWithProblemSolving
       })
-      this.meta.totalDays++
-      this.meta.strategy[strategy]++
     }
   },
   getters: {
diff --git a/src/modules/lean/strategy.ts b/src/modules/lean/strategy.ts
index ac4ea90..fe42282 100644
--- a/src/modules/lean/strategy.ts
+++ b/src/modules/lean/strategy.ts
@@ -1 +1 @@
-export type Strategy = 'push' | 'pull' | 'turn-off'
+export type Strategy = 'push' | 'pull' | 'problem-solving'