exercise 4 done

src/sa/model/features.fml1

@@ -0,0 +1,64 @@
+feature root "SmartHut"
+    feature ui "User interface"
+        feature web "Web app"
+        feature ios "iOS app"
+        feature android "Android app"
+        feature desktop "Desktop/electron app"
+    feature backend "Backend"
+        feature api "API"
+            feature rest "REST"
+            feature soap "SOAP"
+            feature socket "WebSocket"
+        feature bl "Business logic"
+            feature inout "Input-output propagation"
+            feature sensors "Sensors"
+            feature scenes "Scenes" 
+            feature trig "Triggers"
+            feature aut "Automation"
+    feature device "IoT device integration"
+        feature homekit "HomeKit API"
+        feature echo "Echo API"
+        feature google "Google API"
+    feature scripts "Deployment scripts"
+        feature docker "Docker images"
+            feature xdd "x86-64 Linux"
+            feature xss "x86 Linux"
+            feature arm "ARM Linux"
+            feature win "x86-64 Windows image"
+        feature dcomp "docker-compose script"
+            feature va "v3.8"
+            feature vb "v2.4"
+            feature vc "v1"
+
+root has ui
+root has backend
+root has device
+root has scripts
+ui has web
+ui canHave android
+ui canHave ios
+ui canHave desktop
+backend has api
+backend has bl
+bl has inout
+bl has sensors
+bl has scenes
+bl canHave trig
+bl canHave aut
+api canHave rest
+api canHave soap
+api has socket
+device hasSome [homekit, echo, google]
+scripts has docker
+scripts has dcomp
+dcomp hasOneOf [va, vb, vc]
+docker canHave xss
+docker canHave arm
+docker canHave win
+docker has xdd
+
+ui requires api
+rest excludes soap
+api requires bl
+aut requires trig
+aut requires scenes

src/sa/model/index.md

@@ -424,6 +424,29 @@ Exceed: Include more than 8 non-trivial features, indicate which are found in yo
 
 }
 
+By "competitor" I choose to consider the existing application as it has been developed for the 2020 edition of SA4, comparing what has already been implemented to what needs to be implemented.
+
+Here is a list of features included in the existing application. All other features therefore need to / could be implemented or replace existing features.
+
+- User Interface
+  - Web app
+- Backend
+  - API
+    - REST
+    - WebSocket
+  - Business Logic
+    - Input-output propagation
+    - Sensors
+    - Scenes
+  - Deployment scripts
+    - Docker images
+      - x66-64 linux
+    - docker-compose script
+      - v2.4
+  
+
+
+![Feature Model Diagram](./features.fml1)
 
 # Ex - Context Diagram