Element 010: Report on case study based modelling of 2000 words (2019 MOD002665 TRI2 F01CHE)

Sample Answer

Case Study Based Simulation Modelling Report

Introduction

This report presents a case study based simulation modelling exercise focused on an operational system relevant to supply chain and logistics performance. The aim is to analyse the current system, build a simulation model using Witness software, validate the model against observed behaviour, and propose improvements that enhance efficiency, reduce delays, and optimise resource utilisation.

Simulation modelling is widely used in operations management because it allows decision-makers to test “what-if” scenarios without disrupting real-world operations. In this context, it helps identify bottlenecks, inefficiencies, and capacity constraints before implementing costly changes.

For this assignment, a warehouse order fulfilment and dispatch system is selected as the case study system. This type of system is highly suitable because it involves clear process flows, measurable performance data (such as processing time, queue lengths, and throughput), and realistic constraints such as labour availability and transport scheduling.

System Description and Problem Definition

The selected system represents a medium-sized warehouse responsible for receiving customer orders, picking items, packing them, and dispatching them to transport providers.

System Structure

The system consists of the following key stages:

• Order receipt and entry into the system
• Inventory checking and picking from storage
• Packing and quality control
• Dispatch and loading onto transport vehicles

Resources involved include warehouse staff, picking stations, packing stations, and limited transport loading bays.

Key Problems Identified

The system currently suffers from several operational inefficiencies:

Firstly, there are frequent delays in order processing due to uneven workload distribution between picking and packing stations. This leads to queue build-ups, particularly during peak order periods.

Secondly, resource utilisation is unbalanced. Picking stations are often overloaded while packing stations remain underutilised at certain times, creating inefficiency in labour allocation.

Thirdly, dispatch delays occur due to limited loading bays, causing finished orders to wait even after processing is complete.

Finally, variability in order arrival rates creates unpredictability in system performance, making it difficult to maintain consistent throughput.

The objective of this simulation is to model these issues, validate system behaviour, and test potential improvements.

Current System Modelling, Verification and Validation (Witness Model)

Model Construction

The current system is modelled in Witness using the following components:

• Entities: customer orders
• Processes: picking, packing, dispatch
• Resources: warehouse staff, packing stations, loading bays
• Queues: order backlog, picking queue, dispatch queue

Processing times are defined based on observed operational averages, with variability introduced to reflect real-world uncertainty.

Model Behaviour

The simulation of the current system shows the following patterns:

• High queue accumulation at picking stage
• Idle time in packing stations during off-peak periods
• Bottleneck formation at dispatch stage due to limited loading capacity
• Overall system throughput constrained by picking capacity

Verification and Validation

The model is verified by checking logical flow consistency, ensuring no process deadlocks and confirming that entities move correctly through each stage.

Validation is achieved by comparing simulated output with historical operational data. The model reflects realistic system behaviour, particularly in queue formation and throughput rates, confirming its suitability for scenario testing.