diff --git a/bopytex/scheduler.py b/bopytex/scheduler.py
index 34b68b7..0e22d98 100644
--- a/bopytex/scheduler.py
+++ b/bopytex/scheduler.py
@@ -16,11 +16,13 @@ class Scheduler:
         self._tasks = []
 
     @property
-    def tasks(self):
+    def tasks(self) -> list[Task]:
+        """ list all the tasks """
         return self._tasks
 
     @property
-    def doable_tasks(self):
+    def doable_tasks(self) -> list[Task]:
+        """ list all doable tasks """
         return [
             task
             for task in self.tasks
@@ -28,15 +30,17 @@ class Scheduler:
         ]
 
     @property
-    def all_deps(self):
+    def all_deps(self) -> list[str]:
+        """ List dependencies of all tasks """
         return {d for task in self.tasks for d in task.deps}
 
     @property
-    def all_output(self):
+    def all_output(self) -> list[str]:
+        """ List ouput of all tasks """
         return {task.output for task in self.tasks}
 
     @property
-    def done(self):
+    def done(self) -> list[str]:
         return self._done
 
     def append(self, tasks: list[Task]):
@@ -54,24 +58,14 @@ class Scheduler:
         return self.next()
 
     def next(self):
-        undoable = []
-
         try:
-            task = self._tasks.pop(0)
+            task = self.doable_tasks[0]
         except IndexError:
             raise StopIteration
 
-        while not all([d in self.done for d in task.deps]):
-            undoable.append(task)
-            try:
-                task = self._tasks.pop(0)
-            except IndexError:
-                self.append(undoable)
-                raise StopIteration
-
-        self.append(undoable)
         ans = self.dispatch(task)
         self._done.append(task.output)
+        self._tasks.remove(task)
         return ans
 
     def run(self):