How-To

Given the failure of a resource, how does this this affect your delivery time?

Simulation Modeling and Analysis

Downtime Modeling
- Build probability distributions or schedules for resource downtime in your FlexSim model (e.g., Mean Time Between Failures (MTBF) and Mean Time To Repair (MTTR)).
Scenario Analysis
- Run scenarios where a critical machine fails for a certain duration. Observe queue build-up, lead time, and any additional delays downstream.
Contingency Testing
- Test alternative routings or backup resources in the model. Track how quickly WIP recovers and how delivery times are affected.
Sensitivity Analysis
- Vary the time or frequency of failures to measure how robust your system is. This helps assess risk and potential recovery strategies.

Lean Thinking Principles

Redundancy vs. Efficiency
- Lean typically minimizes excess inventory or backup machines, but some redundancy might be necessary for critical processes to ensure uninterrupted flow.
Poka-Yoke (Error Proofing)
- If a failure is frequently triggered by a particular cause, implement error-proofing or preventive maintenance to reduce downtime risk.
Preventive Maintenance (TPM)
- Lean’s Total Productive Maintenance (TPM) focuses on proactively caring for equipment to reduce unplanned failures and maintain steady flow.
Buffer Management
- While Lean seeks to reduce unnecessary inventory, strategic buffer stocks before the most failure-prone resource can protect the downstream flow when a failure occurs.

Where should you allocate resources?

Simulation Modeling and Analysis 1. Scenario Testing * Create multiple scenarios in the simulation model. For instance, add or remove a machine or operator at different stations and observe the outcomes. 2. Key Metrics * Track lead time, throughput, and resource utilization for each scenario. * Compare scenarios to see which resource allocation

Building a Process Flow in FlexSim

Creating a clear, structured process flow is the foundation of any effective simulation model. Whether you’re analyzing a manufacturing line, an airport operation, or a service workflow, the goal is the same: define the activities, connect them logically, allocate the right resources, and control the flow of events. This

Which job should you schedule first? In what sequence?

Simulation Modeling and Analysis 1. Dispatching Rules * Program or set different scheduling heuristics (e.g., First-In-First-Out (FIFO), Earliest Due Date (EDD), Shortest Processing Time (SPT), etc.) in your FlexSim model. 2. Batch or Sequence Comparison * Experiment with various sequences in simulation (e.g., schedule high-priority orders first vs. regular jobs

Where Is the Bottleneck? A Practical Guide to Simulation Modeling and Analysis

Operational problems rarely announce themselves. Instead, queues silently expand, delays accumulate, and throughput declines mysteriously.