diff --git a/config/platform_demo.yml b/config/platform_demo.yml
index 0a2e945..01a37e4 100644
--- a/config/platform_demo.yml
+++ b/config/platform_demo.yml
@@ -20,10 +20,10 @@ mod_system_config:
     dispatcher: "OSP"        # 3 options: GI, SBA, OSP
     rebalancer: "NPO"        # 2 options: NONE, NPO, RVS
   fleet_config:
-    fleet_size: 2000
+    fleet_size: 1000
     veh_capacity: 6
   request_config:
-    request_density: 1    # <= 1
+    request_density: 0.5    # <= 1
     max_pickup_wait_time_min: 5
     max_onboard_detour: 1.3   # < 2
 simulation_config:
diff --git a/src/dispatcher/ilp_assign.cpp b/src/dispatcher/ilp_assign.cpp
index 695982a..acfbc27 100644
--- a/src/dispatcher/ilp_assign.cpp
+++ b/src/dispatcher/ilp_assign.cpp
@@ -109,19 +109,14 @@ std::vector<size_t> IlpAssignment(const std::vector<SchedulingResult> &vehicle_t
                 }
             }
         }
+//        fmt::print("\n[GUROBI] Objective:{}.\n", model.get(GRB_DoubleAttr_ObjVal));
 
     } catch(GRBException e) {
-        std::cout << "Error code = " << e.getErrorCode() << std::endl;
-        std::cout << e.getMessage() << std::endl;
+        fmt::print("\n[GUROBI] Error code = {} ({}).\n", e.getErrorCode(), e.getMessage());
     } catch(...) {
-        std::cout << "Exception during optimization" << std::endl;
-    }
-
-
-
-    if (DEBUG_PRINT) {
-        TIMER_END(t)
+        fmt::print("Exception during optimization\n");
     }
+    if (DEBUG_PRINT) { TIMER_END(t) }
     return selected_vehicle_trip_pair_indices;
 }
 
diff --git a/src/dispatcher/scheduling.cpp b/src/dispatcher/scheduling.cpp
index bfd0199..7dc1b00 100644
--- a/src/dispatcher/scheduling.cpp
+++ b/src/dispatcher/scheduling.cpp
@@ -5,31 +5,29 @@
 #include "scheduling.hpp"
 
 uint64_t ComputeScheduleCost(const std::vector<Waypoint> &schedule,
-                                    const std::vector<Order> &orders,
-                                    const Vehicle &vehicle,
-                                    uint64_t system_time_ms) {
-    auto cost_pickup_ms = 0;
-    auto cost_dropoff_ms = 0;
+                             const std::vector<Order> &orders,
+                             const Vehicle &vehicle,
+                             uint64_t system_time_ms) {
     auto accumulated_time_ms = vehicle.step_to_pos.duration_ms;
+    auto cost_pickup_delay_ms = 0;
+    auto cost_total_delay_ms = 0;
 
     for (const auto &wp : schedule) {
         accumulated_time_ms += wp.route.duration_ms;
     }
-    return accumulated_time_ms;
 
-//    for (const auto &wp : schedule) {
-//        accumulated_time_ms += wp.route.duration_ms;
-//        if (wp.op == WaypointOp::PICKUP) {
-//            cost_pickup_ms += system_time_ms + accumulated_time_ms - orders[wp.order_id].request_time_ms;
-//            assert(system_time_ms + accumulated_time_ms - orders[wp.order_id].request_time_ms >= 0);
-//        }
-//        if (wp.op == WaypointOp::DROPOFF) {
-//            cost_dropoff_ms += system_time_ms + accumulated_time_ms -
-//                               (orders[wp.order_id].request_time_ms + orders[wp.order_id].shortest_travel_time_ms);
-//            assert(system_time_ms + accumulated_time_ms -
-//                   (orders[wp.order_id].request_time_ms + orders[wp.order_id].shortest_travel_time_ms) >= 0);
-//        }
-//    }
-//    auto cost_ms = cost_pickup_ms + cost_dropoff_ms;
-//    return cost_ms;
+    for (const auto &wp : schedule) {
+        accumulated_time_ms += wp.route.duration_ms;
+        if (wp.op == WaypointOp::PICKUP) {
+            cost_pickup_delay_ms += system_time_ms + accumulated_time_ms - orders[wp.order_id].request_time_ms;
+            assert(system_time_ms + accumulated_time_ms - orders[wp.order_id].request_time_ms >= 0);
+        }
+        if (wp.op == WaypointOp::DROPOFF) {
+            cost_total_delay_ms += system_time_ms + accumulated_time_ms -
+                               (orders[wp.order_id].request_time_ms + orders[wp.order_id].shortest_travel_time_ms);
+            assert(system_time_ms + accumulated_time_ms -
+                   (orders[wp.order_id].request_time_ms + orders[wp.order_id].shortest_travel_time_ms) >= 0);
+        }
+    }
+    return cost_total_delay_ms;
 }
\ No newline at end of file
diff --git a/src/dispatcher/scheduling_impl.hpp b/src/dispatcher/scheduling_impl.hpp
index 2bb8a14..bf58015 100644
--- a/src/dispatcher/scheduling_impl.hpp
+++ b/src/dispatcher/scheduling_impl.hpp
@@ -24,9 +24,9 @@ SchedulingResult ComputeScheduleOfInsertingOrderToVehicle(const Order &order,
     int violation_type;
     for (const auto &sub_schedule: sub_schedules) {
         const auto num_wps = sub_schedule.size();
-        // insert the order's pickup point
+        // Insert the order's pickup point.
         for (int pickup_idx = 0; pickup_idx <= num_wps; pickup_idx++) {
-            // insert the order's drop-off point
+            // Insert the order's drop-off point.
             for (int dropoff_idx = pickup_idx; dropoff_idx <= num_wps; dropoff_idx++) {
                 auto new_schedule = GenerateScheduleFromSubSchedule(
                         order, vehicle, sub_schedule, pickup_idx, dropoff_idx, router_func);
@@ -40,10 +40,6 @@ SchedulingResult ComputeScheduleOfInsertingOrderToVehicle(const Order &order,
                     }
                     scheduling_result.success = true;
                     scheduling_result.feasible_schedules.push_back(std::move(new_schedule));
-
-//                    // for gi debug
-//                    assert(scheduling_result.best_schedule_idx == 0 && scheduling_result.feasible_schedules.size() == 1);
-//                    return scheduling_result;
                 }
                 if (violation_type > 0) { break; }
             }
diff --git a/src/simulator/types.hpp b/src/simulator/types.hpp
index 7330c29..e84e955 100644
--- a/src/simulator/types.hpp
+++ b/src/simulator/types.hpp
@@ -129,7 +129,7 @@ struct Waypoint {
 enum class VehicleStatus {
     IDLE,          // the vehicle has no task and stays stationary
     WORKING,       // the vehicle is serving orders
-    REBALANCING    // the vehicle is moving towards a high demand area
+    REBALANCING    // the vehicle is moving towards a reposition location to improve future performance
 };
 
 inline std::string vehicle_status_to_string(const VehicleStatus &s) {