diff --git a/examples/nested_decision_execution/rl_dummy.py b/examples/nested_decision_execution/rl_dummy.py
index 1ea444cdf..3eec91789 100644
--- a/examples/nested_decision_execution/rl_dummy.py
+++ b/examples/nested_decision_execution/rl_dummy.py
@@ -1,7 +1,7 @@
 import pickle
 from dataclasses import dataclass, asdict
 from pprint import pprint
-from typing import Iterable, Any, Optional, Tuple, Dict
+from typing import Iterable, Any, Optional, Tuple, Dict, List
 
 import gym
 import numpy as np
@@ -128,6 +128,48 @@ class EpisodicState:
         }
         return logs
 
+    @classmethod
+    def from_order_and_executor(cls, order: Order, executor: BaseExecutor, frequency: str) -> "EpisodicState":
+        # Synchronous state for executor to EpisodicState
+        executor.reset(start_time=order.start_time, end_time=order.end_time)
+        state = cls(
+            stock_id=order.stock_id,
+            start_time=order.start_time,
+            end_time=order.end_time,
+            direction=order.direction,
+            target=order.amount,
+            num_step=executor.trade_calendar.get_trade_len(),
+            market_price=_retrieve_backtest_data(order, '$close', frequency),
+            market_vol=_retrieve_backtest_data(order, '$volume', frequency),
+        )
+        state.cur_step = executor.trade_calendar.get_trade_step()
+        assert state.cur_step == 0
+        state.cur_time, _ = executor.trade_calendar.get_step_time(state.cur_step)
+        return state
+
+    def update(self, execute_result: List[Order], executor: BaseExecutor) -> "StepState":
+        exec_vol = np.array([order.deal_amount for order, _, __, ___ in execute_result])
+        # Synchronous exec_vol to executor and synchronous back to EpisodicState
+        calendar = executor.trade_calendar
+        cur_tick = self.cur_tick
+        ticks_this_step = len(exec_vol)
+        self.cur_step = trade_step = calendar.get_trade_step()
+        self.cur_tick += ticks_this_step
+        self.position -= np.sum(exec_vol)
+        self.position_history[trade_step] = self.position
+        self.done = executor.finished()
+        self.exec_vol = exec_vol if self.exec_vol is None else \
+            np.concatenate((self.exec_vol, exec_vol))
+
+        if self.done:
+            self.update_stats()
+        else:
+            self.cur_time, _ = calendar.get_step_time(trade_step)
+
+        l, r = cur_tick, cur_tick + ticks_this_step
+        assert 0 <= l < r
+        return StepState(exec_vol, self.market_vol[l:r], self.market_price[l:r], self)
+
 
 @dataclass
 class StepState:
@@ -158,6 +200,28 @@ class StepState:
                                        self.episode_state.direction)
 
 
+def _retrieve_backtest_data(order: Order, field: str, frequency: str) -> np.ndarray:
+    # Retrieve backtest data for RL-specific use (including reward calculation)
+    return D.features(
+        [order.stock_id],
+        ['$open', '$close', '$high', '$low', '$volume'],
+        start_time=order.start_time,
+        end_time=order.end_time,
+        freq=frequency
+    )[field].to_numpy()
+
+
+def create_sub_order(exec_vol: float, executor: BaseExecutor, original_order: Order) -> Order:
+    # Convert a real number to an order
+    calendar = executor.trade_calendar
+    trade_step = calendar.get_trade_step()
+    trade_start_time, trade_end_time = calendar.get_step_time(trade_step)
+    order_kwargs = asdict(original_order)
+    order_kwargs.update(start_time=trade_start_time, end_time=trade_end_time, amount=exec_vol)
+    trade_decision = Order(**order_kwargs)
+    return trade_decision
+
+
 class SingleOrderEnv(gym.Env):
     def __init__(self,
                  observation: StateInterpreter,
@@ -181,66 +245,6 @@ class SingleOrderEnv(gym.Env):
     def observation_space(self):
         return self.observation.observation_space
 
-    def retrieve_backtest_data(self, field: str):
-        # Retrieve backtest data for RL-specific use (including reward calculation)
-        return D.features(
-            [self.cur_order.stock_id],
-            ['$open', '$close', '$high', '$low', '$volume'],
-            start_time=self.cur_order.start_time,
-            end_time=self.cur_order.end_time,
-            freq=self.inner_frequency
-        )[field].to_numpy()
-
-    def initialize_state(self):
-        # Synchronous state for executor to EpisodicState
-        self.executor.reset(start_time=self.cur_order.start_time, end_time=self.cur_order.end_time)
-        state = EpisodicState(
-            stock_id=self.cur_order.stock_id,
-            start_time=self.cur_order.start_time,
-            end_time=self.cur_order.end_time,
-            direction=self.cur_order.direction,
-            target=self.cur_order.amount,
-            num_step=self.executor.trade_calendar.get_trade_len(),
-            market_price=self.retrieve_backtest_data('$close'),
-            market_vol=self.retrieve_backtest_data('$volume'),
-        )
-        state.cur_step = self.executor.trade_calendar.get_trade_step()
-        assert state.cur_step == 0
-        state.cur_time, _ = self.executor.trade_calendar.get_step_time(state.cur_step)
-        return state
-
-    def update_state(self, exec_vol):
-        # Synchronous exec_vol to executor and synchronous back to EpisodicState
-        calendar = self.executor.trade_calendar
-        state = self.ep_state
-
-        trade_step = calendar.get_trade_step()
-        trade_start_time, trade_end_time = calendar.get_step_time(trade_step)
-        order_kwargs = asdict(self.cur_order)
-        order_kwargs.update(start_time=trade_start_time, end_time=trade_end_time, amount=exec_vol)
-        trade_decision = Order(**order_kwargs)
-        execute_result = self.executor.execute([trade_decision])
-        cur_tick = state.cur_tick
-
-        inner_exec_vol = np.array([order.deal_amount for order, _, __, ___ in execute_result])
-        ticks_this_step = len(inner_exec_vol)
-        state.cur_step = trade_step = calendar.get_trade_step()
-        state.cur_tick += ticks_this_step
-        state.position -= np.sum(inner_exec_vol)
-        state.position_history[trade_step] = state.position
-        state.done = self.executor.finished()
-        state.exec_vol = inner_exec_vol if state.exec_vol is None else \
-            np.concatenate((state.exec_vol, inner_exec_vol))
-
-        if state.done:
-            state.update_stats()
-        else:
-            state.cur_time, _ = calendar.get_step_time(trade_step)
-
-        l, r = cur_tick, cur_tick + ticks_this_step
-        assert 0 <= l < r
-        return StepState(inner_exec_vol, state.market_vol[l:r], state.market_price[l:r], state)
-
     def reset(self):
         try:
             self.cur_order = next(self.dataloader)
@@ -249,7 +253,9 @@ class SingleOrderEnv(gym.Env):
             return None
 
         self.execute_result = []
-        self.ep_state = self.initialize_state()
+        self.ep_state = EpisodicState.from_order_and_executor(
+            self.cur_order, self.executor, self.inner_frequency
+        )
 
         self.action_history = np.full(self.ep_state.num_step, np.nan)
         return self.observation(self.ep_state)
@@ -260,7 +266,9 @@ class SingleOrderEnv(gym.Env):
         self.action_history[self.ep_state.cur_step] = action
 
         exec_vol = self.action(action, self.ep_state)
-        step_state = self.update_state(exec_vol)
+        trade_decision = create_sub_order(exec_vol, self.executor, self.cur_order)
+        execute_result = self.executor.execute([trade_decision])
+        step_state = self.ep_state.update(execute_result, self.executor)
         if self.executor.finished():
             assert self.ep_state.done