Building Robust Bills of Operations: Real World Examples

In the world of specialty vehicle manufacturing, efficient production processes are vital to meet customer demands and achieve growth. At Optegrity Solutions, we have found a comprehensive operations management system that enables Lean transformation for manufacturers producing complex products through assembly lines and value streams. A foundational concept in this system is the “Bill of Operations,” which complements the well-known Bill of Materials.

What is a Bill of Operations?

A Bill of Operations (BoO) is a set of necessary operations performed during the manufacturing process. While a Bill of Materials defines “what” goes into the final product, the BoO covers the labor side of production. Like modular BOMs, BoOs use “Operations” as medium-sized labor elements, providing flexibility, reusability, and optimization.

Designing the Bill of Operations:

To design a robust Bill of Operations, let’s consider Op-T, a specialty vehicle manufacturing plant producing Op-T Trucks. We’ll break down the process into the following steps:

  1. Establish Takt Time: Takt Time is calculated as available production time divided by customer demand. So if demand is 100 units per week with a 40 hour work week, then Takt Time is 24 minutes. (40 hrs / 100 units = 0.4 hrs = 24 minutes)
  2. Define Operations: Follow the rule of thumb for medium-sized Operations (around 1/5th of the shortest Takt Time). Target cycle time for each Operation should be approximately 5 man-minutes of labor content.
  3. Process Mapping and Time Studies: Document and time the process from Fabrication to Final Quality Check, creating a list of production steps and labor content time.
  4. Assign Operations to Operators and Cells: Assign Operations to Operators ensuring they can complete their workload within Takt Time, using Yamazumi charts for level loading.

Managing Complexity:

In real-world scenarios, products often have varying requirements, leading to complexity in manufacturing. To manage complexity, categorize Operations as Common and Incremental. Consider approaches like Deferred Complexity, Built-In Complexity, or a Hybrid approach to address Incremental Operations.

Benefits of Robust Operations on the Shop Floor:

Having a well-defined Bill of Operations brings several benefits to a specialty vehicle manufacturing plant:

  1. Increased Efficiency: Robust Operations optimize production processes, reducing waste and bottlenecks.
  2. Flexibility: The modular nature of BoO allows for quick adjustments to meet changing customer demands and Takt Time.
  3. Resource Utilization: Proper allocation of Operators and Cells leads to efficient resource utilization and reduced work in process.
  4. Improved Productivity: Streamlined operations enhance throughput, leading to increased production and quicker cash generation.
  5. Lean Transformation: Implementing BoO aligns with Lean Manufacturing principles, enabling continuous improvement and waste reduction.


Designing a robust Bill of Operations is a crucial step for specialty vehicle manufacturing plants aiming for Lean transformation. With the right Operations planning and analysis, manufacturers can achieve greater efficiency, flexibility, and productivity on the shop floor. Embracing Lean principles and adopting a growth mindset can lead to amazing results and sustainable growth in the long run. For more information or assistance in building your own BoO, contact us at Optegrity Solutions by emailing Josh@OptegritySolutions.

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