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by Tony Soares

The task of the Quality Systems Group at Siemens Westinghouse Power Corp. was challenging: It endeavored to systematically implement a supplier-facing standardized product- and process-qualification process for gas turbine blades. The new process would help reduce PPQ cycle time, eliminate or minimize product failure points downstream, reduce scrap and improve first-time yield.

In the highly complex and demanding power-generation industry, business success depends on effective collaboration with suppliers to ensure superior, reliable and efficient designs; rapid planning to production cycle time; and containment of development and manufacturing costs. For SWPC, the main business objective was to improve economic performance while achieving customer satisfaction and strategic supplier relationships through standardized processes and consistent methodologies.

Headquartered in Orlando, Florida, SWPC is the regional business entity in the Americas for Siemens Power Generation’s global fossil power generation business, which has an installed fleet of more than 600,000 megawatts worldwide. Siemens Power Generation offers a full spectrum of products and services throughout the entire power plant life cycle, including gas and steam turbines, electric generators, process control and power management systems, and fuel cells for the distributed generation market.

With about 250 multi-tier suppliers across the globe providing components for gas turbines, the supplier quality management function plays a vital role in the sourcing process. Gas turbine blades require one of the most complex sourcing processes, involving up to five unique sourcing steps:

1. Investment casting

2. Root machining

3. Cooling hole drilling (electrical discharge machining and electro-chemical machining)

4. Diffusion and ceramic coatings

5. Airflow testing and moment weight

The process of designing a turbine blade is inherently complex, involving precise and unique product characteristics such as high-strength and high-temperature alloys, thermal barrier coating, and complex cooling to withstand extreme turbine operating temperatures and tight dimensional tolerances. Meeting the stringent requirements of the design intent and close-to-zero-tolerance for failures requires the skills of many design, manufacturing and quality professionals across various organizations. This makes the design and qualification process for gas turbine blades highly collaborative and complex.

In pursuit of continuous process improvement

With the suspicion that variation in the PPQ process was affecting optimization of first-time yield, SWPC conducted a Six Sigma study of the turbine blade PPQ process and its effect on the costs of poor quality, such as scrap and rework. Given the complexity of the turbine blade, the study hypothesized that an ability to define and solve problems collaboratively with suppliers through standardized processes at the early stages of the supplier manufacturing process development cycle can significantly improve downstream reaction times and costs. The Six Sigma study was completed in October 2001. The findings confirmed the group’s suspicions.

After reviewing the data collected during the measurement phase of the study and comparing them with the goals of a closed-loop PPQ process, it was apparent that the existing PPQ process failed to map these goals. The Six Sigma study also identified a direct link between the up-front effort put into process development and qualification as well as the nonconformance costs. Among other improvements, the study demonstrated that a standardized, closed-loop PPQ process with consistent methodologies would improve first-time yield, thereby reducing or eliminating rework cycles and scrap.

A standardized closed-loop PPQ process must:

Minimize supplier product nonconformance

Minimize PPQ cycle time with suppliers

Ensure ongoing process control

Predict future quality

Provide visibility across PPQs

Document the qualification process

Provide complete documentation of qualification

Effectively balance workload and resources

Furthermore, the Six Sigma study concluded that a system leveraging the Internet would drive the PPQ process in a way that steers suppliers to focus on up-front process development as opposed to the current practice of creating a basic process and modifying it after full production has begun.

Features of a supplier quality collaboration system

The unique characteristics of its product lines and the multitude of plants and suppliers across the world require that SWPC operates within a complex network of supplier relationships. Defining the key requirements of a Web-based system that would help enforce a standardized PPQ process at SWPC and across its suppliers was a daunting challenge. After careful evaluation and following rigorous Six Sigma process, the Quality Systems Group put together a detailed plan of reorganizing the PPQ process and revitalizing the fundamental principle of quality: “Do it right the first time.”

PPQ management

PPQ management across suppliers reduces cycle time, rework and scrap while improving first-time yield. One issue found when reviewing the PPQ process was a need for increased control of PPQs from an administrative standpoint. It was often difficult to track the status of PPQs and action items. Improvements allowing the system to track the entire PPQ process life cycle across suppliers, from planning to final production release, as well as providing accountability and transparency across PPQs, helped optimize resources.

Standardized workflow

SWPC suppliers collaborate with the organization’s engineering and manufacturing teams across multiple parts, product lines, competency centers and plants. Therefore, the system should be able to standardize new methodologies such as failure mode and effects analysis and critical to quality characteristics, and reinforce existing methodologies, such as manufacturing and quality control plan, gage repeatability and reproducibility, and process capability across multiple parts, products, plants and suppliers. This ensures faster acceptance of the system by suppliers.


Template-driven standard documentation

Review of the past PPQ records revealed that there was no common format that suppliers could follow to ensure consistency. With a poorly organized PPQ record package comes a difficult review process. To address this challenge, the system should provide a standard, template-driven PPQ record package that can aid engineers in performing an adequate review of the supplier-provided documentation.

Single source of information

Engineers and suppliers often spend a significant amount of time trying to find the right information at the right place and at the right time. While managing the entire PPQ life cycle, the system should also provide a single source of truth--a source where any team member can access information about the PPQ process in real time.

Consistent process metrics

Supplier quality excellence through continuous improvement is one of SWPC’s cornerstones. Its closed-loop PPQ system should be active 24 X 7 to monitor compliance, detect exceptions, link to critical reports, measure processes across consistent metrics and KPIs, provide graphical trends, send alerts and notifications, and capture lessons learned. For SWPC, a configurable dashboard, which provides an aggregated view into these quality metrics across plants, suppliers and product lines and supports views relevant to a user’s perspective, was essential.

Security protects intellectual property and competitive edge

As the PPQ system enables supplier-facing processes, security is of paramount importance. Who has access to the system and to what data, which user can perform what task, and how the data are shared on a need-to-know basis are critical factors. The system should provide both process and data-level security to prevent unauthorized users from accessing the data.

Flexible system ensures supply base agility

The repeated use of common processes is essential to supply base agility. SWPC has multiple product lines with complex parts, global plants and competency centers, and a supply base that extends across geographies. Its system should be flexible enough to be easily migrated and rolled out to other product lines, competency centers and plants as well as to a constantly changing supply base.

Issues with homegrown systems

Initially, the Quality Systems Group considered two alternatives to address the complex needs of this standardized process:

Extend the existing in-house PPQ system. Internal development and enhancement of SWPC’s in-house database was considered a short-term fix to track key milestones of the PPQ process. This option was quickly discarded because:

  • The system was not Web-based.
  • It was within SWPC’s four walls and could not be accessed by suppliers.
  • It could not scale to handle all of Siemens’ power-generation divisions.
  • It was too manually intensive.

Develop a new Web-based PPQ system in-house. This option was also considered inappropriate due to time and cost constraints. To design a system with such complexity would simply take too long. Processes change as business evolves, and it would be extremely difficult and costly to maintain this evolving change internally.

In mid-2003, SWPC went live with Apexon Inc., a San Jose, California-based company that develops Web-based supplier quality collaboration solutions for global manufacturing companies.

In addition to meeting the key requirements mentioned, SWPC had the following criteria when choosing a PPQ system. The system needed to:

Have been implemented and tested under similarly complex environment

Be able to leverage SWPC’s current IT investments such as the SAP ERP system

Be easy to use by internal teams and suppliers and require minimal training

Be an out-of-box solution that could be implemented quickly and with reliable support

Positive growth measurements

Cycle time. SWPC now has in place a cross-company, closed-loop standardized PPQ process that reinforces consistent methodologies with its suppliers throughout the PPQ process life cycle, from planning to final production release. SWPC has seen significant reduction in its PPQ cycle time.

Costs of poor quality. SWPC is now able to centrally manage its cross-company PPQ system to drive design-for-manufacturability verification early in the design cycle, delivering optimized, robust designs into production to reduce scrap and rework costs.

Travel costs. Before, members of the PPQ team would frequently travel to suppliers across the globe to ensure that all of Siemens’ requirements were understood and fulfilled. Today, Siemens has significantly reduced such costs, as most problems and issues are now addressed electronically through the process.

Resource optimization. Design, manufacturing and quality engineers are highly trained and specialized. With a standardized PPQ process, SWPC now ensures that its engineers are spending their time on higher-value improvement projects instead of mundane administrative activities, thus making them more productive.

Expansion. Siemens is currently rolling out the system to other Siemens power-generation manufacturing plants to a new set of suppliers, new plants and competency centers.

Supplier enthusiasm. As the extension continues, the implementation of a closed-loop standardized PPQ process has been applauded, supported and enthusiastically embraced by the receiving users, such as the internal members of SWPC and the entire supplier community.

Driving design for quality

From the start, this project was based on one fundamental principle of quality: Do it right the first time. The question was: How can SWPC help suppliers do it right the first time? And how can SWPC drive these suppliers to develop processes that provide defect-free products from the first piece produced?

The answer is to ensure a robust and standardized PPQ for every product and process. Target product- and process-specific qualifications, and incorporate appropriate tools into the process so that both manufacturer and suppliers can use them to support development of this robust process. This will drive up-front quality. The benefits of such standardization go even beyond improving first-time yield to other nonconformance costs, such as rework expenses, nonconformance-related production delays and engineering time spent dealing with nonconformance disposition.

About the author

Tony Soares is quality systems manager at Siemens Westinghouse Power Corp. in Orlando, Florida.

© 2004 Siemens Westinghouse Power Corp. All rights reserved.