Traveling with S-88: Leveraging the ISA-88 Standard in a Complex Assembly Process
Bruce Henne of EaglePicher Technologies, with Marcus Tennant of Rockwell Automation
An Overview:
Complex assembly process overview
Challenges of a complex assembly process
How ISA-88 was applied
Benefits and Conclusion
Questions
Eagle-Picher Technologies...
Based in Joplin, Missouri, is the leading producer of batteries and energetic devices for the defense, space and commercial industries.
Provides a broad capability in battery technology
Energy products and pyrotechnic devices for the defense industry.
Advanced battery chargers and other power solutions for business, industrial and recreational applications
Complex Assembly
The manufacture of aerospace and defense system batteries is a very complex and intricate assembly process .
Complex assembly can be considered a category of discrete manufacturing processes that Involves detailed assembly interjecting active chemical formulation and micro-machined engineering components.
The final product is a complex combination of chemical and electro-mechanical engineering to achieve absolute reliability of performance in life-critical applications.
Examples of other life-critical complex assembly products include:
Life safety devices such as air bag deployment components, critical aircraft landing and navigation instrumentation,
Medical devices such as pacemakers, and
Other large-scale military and defense safety equipment
About the Traveler...
In complex assembly, a traveler is a control plan record-keeping tracking document
Traditionally paper based
Provides and enforces a standard work flow that makes available critical quality data for the complex assembly
Travels with the materials as they go through intermediate operations
Documentation of each of the final assembled products throughout processing
Final record for quality.
Challenges of Complex Assembly:
Calls for a high level of craftsmanship from trained individuals.
Demands a dexterous, thinking and trained individual to perform a work task that cannot be duplicated in automation at a reasonable cost.
Requires the best human attributes in applying intelligence in the assembly process
But provides strong barriers to minimize variations along specific dimensions of the process.
Goal is to achieve a high level of assurance that the procedure was followed exactly and was completely within the tolerance limits.
A Standards-based perspective of examining the system for complex manufacturing is to consider each step in the process as a Level 1 activity in the ISA –95.01 domain hierarchy model.
Every activity should be given a process flow and a standard procedure for the operator to follow to achieve maximum consistency, as in an automated process.
Physical Manufacturing Operations
Lynn Craig in his 2007 WBF paper: S88.01 - A Business Model or an Engineering Implementation?
Describes this level of process as Physical Manufacturing Operations (PMO)
Physically touching raw materials and equipment and carrying out preordained task
Directly impacts not only cost but quality, capacity, reliability, yield, safety, etc.
Complex Assembly in the context of Physical Manufacturing Operations:
In complex manual assembly processes precision and documentation are critical to quality.
Continuing demands on improvement
Maintain system flexibility for change
Web-based Workflow Tools evaluated
Did not have the enforcement capabilities necessary to lock out pathways of deviation by the operators in the assembly process.
For instance, an operator can use the tools to sign and date each step at the completion of the work flow task, when it is required at each sequential step.
MES Applications evaluated
Current MES application did not have the workflow detail.
Focused on S95.01 Level 3 activities around scheduling, materials management, QA, and work cell-related workflow.
No clear pathway to the future introduction of automation.
How ISA88 was applied:
Combined
ISA-88 standard in modularization of the work area
Commercial-of-the-shelf (COTS) Batch package
Issued instructions to the process operators through a web interface (rather than a controller) for detailed Level 1 work instructions
Permitted the same modularization concepts to apply as they would in an automated process.
The requirements of the complex assembly process required the ability to present one instruction step at a time
To force the operator to input data
Respond to any deviation requirements through applying an electronic signature,
Add comments if needed
Record CAPA problem
Building parallel operations
Enabled the capability to perform multi-piece assembly operations that have different timing requirements.
Allows the production system to have the flexibility for producing a sub-assembly, setting the sub-assembly aside in a WIP holding area, and enter additional QA data collection attributes from laboratory procedures or record other electronic system inputs at a later time
Traveler data construction:
A The complete final product traveler is an aggregation of all the individual traveler documents that correspond to each individual sub-assembly.
The individual subassembly travelers are useful for comparing lot-to-lot sub-assemblies.
By following the ISA-88 model in the design of an electronic traveler, all the critical-to-quality control and report parameters in a hierarchical structure was provided.
In design of procedural steps:
Plan to automate or semi-automate several manual equipment phases in the future.
The primary change at the equipment module level will be to redirect the phase from the manual instruction data server to a Programmable Automation Controller (PAC) phase data server via OPC or other communication protocols
No change will be required to the procedural or reporting structure
The Benefits:
Following the ISA-88 methodology when designing the process enabled us to meet requirements on the standards for workflow across all QC and manufacturing functions.
This element of the design is often challenging and involves considerable discussion and negotiation, but makes a better process in the end.
Use of an electronic traveler allows data to be easily analyzed using efficient database tools and allows flexible introduction of new measurement inputs and capabilities.
Effective change management is an inherent important benefit. Changes in procedures, data collection, equipment and QA checkpoints are an integral part of ISA-88 modular method design.
The rigorous enforcement of manufacturing Level 1 manual sequencing,
Forces the immediate discussion of any proposed procedure change
Immediately documents tribal knowledge from highly skilled operators into SOP and electronic records.
Gives significant flexibility to engineering and management to make that change in a modular system
Incorporate new procedures,
Make modifications to data collection, equipment or QA checkpoints
Utilizing the COTS batch system API enables a single mapping or insertion point of data exchange from the equipment layer of Level 1& 2 to Level 3 MES and Level 4 ERP operations
The use of ISA-88 models and methodology in the design of the process from the ground up enables easy incremental automation to be added into the system at appropriate points.
Conclusion:
ISA-88 modular standards applied through a batch application package successfully provided for the development of critically controlled, complex assembled products in the industries such as aerospace and defense
Key benefits are:
Tight control
Efficient tracking and analysis
Standards based, and flexible and modular process control adaptability