Managing ETO change with BOP-driven process planning

ETO manufacturers operate in a world of constant change—design modifications can arise at any stage, disrupting assembly planning. Every change affects materials, assembly sequences, and shop floor execution, leading to delays and costly rework if not managed systematically.

Our previous blog covered effective BOM management in the ETO change process, ensuring engineering updates are reflected in the Manufacturing Bill of Materials (MBOM). But BOM updates alone aren’t enough. The real challenge is translating those changes into executable process plans without disrupting workflows.

This is where the Bill of Process (BOP) planning becomes critical. While MBOM defines what to build, BOP ensures how it’s manufactured—bridging the gap between design and production. This blog explores how a well-managed BOP keeps ETO production agile, minimizing disruptions and maintaining process consistency.

The Challenge: ETO change in assembly planning

Constant design modifications require manufacturing engineers to update process definitions rapidly while ensuring production remains efficient and error-free. Without a structured way to manage these changes, production delays, inconsistencies, and costly rework become inevitable. A well-defined change management process in assembly planning is crucial to maintaining production stability in an environment where customization drives complexity.

The Solution: A Structured approach to Bill of Process management

The Bill of Process (BOP) defines the manufacturing sequence and operations required to produce a specific part or assembly. In an ETO environment, where product designs frequently evolve, maintaining an up-to-date BOP is essential for process stability and production efficiency. A structured workflow allows manufacturing engineers to systematically evaluate engineering changes, update process definitions, and ensure production teams execute the latest assembly procedures with precision.

Use Case: Airplane Winglet Rib Change

Imagine an aerospace manufacturer faced with a design update to an airplane winglet rib. A design update to an airplane winglet rib introduces material and assembly changes, impacting multiple production stages. Without a structured BOP update, misalignment can cause installation errors, delays, and rework.

To implement the change efficiently, every step in the process must be evaluated and updated by manufacturing engineers:

• Left Wing Installation: Ensuring proper alignment with the aircraft structure.
• Service Door Access: Preparing the area for modification.
• Service Inspection: Conducting pre-modification checks.
• Lifting and Placing the Wing End: Positioning the modified winglet rib.
• Electricity Cable Placement: Adjusting cable routing for compatibility.
• Surface Cleaning: Preparing the area for assembly operations.
• Bolting the Assembly: Using predefined tools to secure the winglet.
• Closing the Service Doors: Finalizing the installation process.
• Service Door Inspection: Ensuring proper closure and alignment.

Reviewing MBOM Changes and Updating the BOP

The change management process begins when a manufacturing change notice (MCN) is received. Manufacturing engineers analyze MBOM updates to identify impacted operations, ensuring that every modification is accounted for in the process plan. For the winglet rib change, this involves reviewing assembly sequences to ensure compatibility with the new design. A digital approach enables quick updates to process definitions, integrating new materials and geometrical adjustments seamlessly into production workflows.

Reusing and adapting existing process plans

Rather than creating process definitions from scratch, manufacturing engineers can reuse and modify existing process plans to incorporate changes efficiently. For the winglet rib, they can:

• Adjust assembly operations to accommodate design modifications.
• Modify installation steps while maintaining best practices.
• Reuse validated work instructions to ensure consistency and efficiency.

This approach streamlines change adoption, reduces redundant effort, and ensures that modifications are efficiently translated into executable assembly plans.

Defining and validating manufacturing process plans

Once updates are integrated, manufacturing engineers validate the new process plan to ensure a smooth transition from design to production. For the winglet rib:

• Virtual assembly simulations check for collisions in the updated installation sequence.
• Quality control checkpoints ensure process changes meet final part tolerances.

Validating changes before implementation reduces the risk of production errors, ensuring that process adjustments maintain the validity of the final assembly.

Managing Seamless Data Flow from Design to Shop Floor

BOP management ensures a continuous transfer of updated work instructions to the shop floor. For the winglet rib change, this means:

• Operators receive revised assembly sequences through digital work instructions.
• Technicians access updated reference documents aligned with the new assembly requirements.
• Quality teams receive updated inspection criteria to ensure compliance with design changes.

This structured data flow eliminates miscommunication, minimizes rework, and ensures that every stakeholder in the production process operates with the most current information.

Using 3D visualization for smarter decision-making

Integrated 3D visualization allows manufacturing engineers to assess design changes in real time, improving process planning and execution. In the case of the updated winglet rib:

• Engineers can analyze new part geometry in a digital twin environment.
• Process planners can validate how changes affect workstations, tools, and sequences using a connected Bill of Equipment (BoE).
• Assembly stakeholders can anticipate ergonomic challenges by visualizing updated operations and equipment interactions in the context of the BoE.

This capability enhances decision-making, improves process accuracy, and facilitates smoother adoption of design changes on the shop floor.

Updating process documentation

As part of the structured change management process, manufacturing engineers update reference process plan documents, such as the winglet assembly instructions, using a centralized document management system. This ensures that all relevant stakeholders have access to the latest approved process information, maintaining consistency across production facilities.

Driving efficiency with Bill of Process in ETO change management

As a critical aspect of the ETO manufacturing change process, the Bill of Process ensures that engineering modifications transition seamlessly into production. With a structured approach, manufacturing engineers can:

• Minimize errors and inconsistencies in process planning.
• Reduce time spent manually updating process instructions.
• Maintain full traceability of engineering changes.
• Ensure shop floor teams work with the most up-to-date product data.

How Teamcenter Easy Plan can streamline the Bill of process management

A modern BOP management solution simplifies complex process updates by integrating engineering changes with production planning.

With a Teamcenter Easy Plan, manufacturing engineers ensure that design modifications are seamlessly integrated into production, reducing manual effort, eliminating inconsistencies, and accelerating time-to-market.

It enables:

• Centralized BOP Definition: Links process plans with MBOM for accurate manufacturing sequences.
• Seamless Change Management: Synchronizes MBOM updates, enabling quick impact analysis and process adaptation.
• Digital Work Instructions: Delivers real-time, visual assembly guidance to the shop floor.
• Automated Change Propagation: Ensures process consistency across multiple production sites.
• Process Validation & Optimization: Supports virtual simulations, quality checks, and compliance verification.
• Efficient Collaboration: Connects manufacturing engineers, quality teams, and production planners

By leveraging an integrated solution, manufacturing engineers can optimize process planning, improve collaboration, and maintain production efficiency despite ongoing design modifications. This approach ensures that changes—like those in the winglet rib example—are efficiently translated into executable manufacturing processes, reducing risk and accelerating time to production.