A C++ library for simulating supply chain inventory management systems.

ChainSim simulates daily inventory operations including demand fulfillment, purchase ordering, lead time delays, and stock tracking.

Places fixed-size orders when inventory falls below a calculated reorder point.

PurchaseROP policy(5, 50.0);  // lead time, average daily demand

Calculates optimal order quantities based on ordering and holding costs.

PurchaseEOQ policy(5, 50.0, 100.0, 0.2);  // lead time, demand, ordering cost, holding cost

Reviews inventory at fixed intervals and orders up to a target level.

PurchaseTPOP policy(5, 50.0, 7);  // lead time, average demand, review period

#include "ChainSimBuilder.h"
#include "purchase_policies/PurchaseROP.h"

int main() {
    auto sim = qz::ChainSimBuilder("MySimulation")
        .simulation_length(30)
        .lead_time(5)
        .average_demand(50.0)
        .starting_inventory(100)
        .build();

    sim.initialize_simulation();

    PurchaseROP policy(5, 50.0);
    sim.simulate(policy);

    auto results = sim.get_simulation_records();
}

• CMake 3.15+
• C++17 compiler
• Git

mkdir build && cd build
cmake ..
make
ctest  # Run tests

./chainsim [options]

Key options:

• --policy <ROP|TPOP|EOQ|EBQ|CUSTOM>: Purchase policy
• --simulation_length <days>: Simulation duration
• --average_demand <units>: Mean demand per time unit
• --lead_time <days>: Average delivery delay
• --starting_inventory <units>: Initial stock level
• --log_level <0-2>: Logging verbosity

Example:

./chainsim --policy ROP --simulation_length 60 --average_demand 100

The simulation generates a CSV file with daily records:

• inventory_quantity
• demand_quantity
• procurement_quantity
• purchase_quantity
• sale_quantity
• lost_sale_quantity