Kathryn L. Lueders
NASA White Sands Test Facility
New Mexico State University
In September, 1995, managers for the White Sands Test Facility's NASA Shuttle Logistics Depot proposed two seemingly impossible staff directives: increase productivity by 100% on an engine flushing repair operation, and decrease dock to dock throughput time by 75%. Budget realities compounded these challenges; only minimal dollars were available for adding any required facility space and personnel. Accomplishing these goals would require a complete process reengineering of the engine flushing repair operation. This article documents a successful process reengineering application. What is unusual about this case study is that the reengineering application is directed to a small NASA test facility as opposed to a large corporation as is very often the case.
Background of the Flushing Operation
The NASA Shuttle Logistics Depot at the White Sands Test Facility (WSTF), Las Cruces, NM, performs repair operations on two engine types: the Space Shuttle Orbital Maneuvering Engine and the Reaction Control System (RCS) engine. In 1992, WSTF developed a RCS engine flushing operation. The flushing operation is performed to remove contaminants from the oxidizer propellant valve mounted on each engine. The contamination degrades the valve and therefore engine performance, as well as causes propellant leakage.
Prior to the development of the flush procedure, the standard repair for a leaking valve on a RCS engine was a valve removal and replacement. WSTF introduced the RCS engine flushing process in 1992 as a cost-saving measure and also as a way to quickly provide critical spares. The flushing procedure fixed the leakage problem over 60% of the time. In addition, the operation provided a significant cost and schedule advantage. Cost for the procedure was only 7.1% of the 1992 valve removal and replacement price; and the procedure was performed in 1.9% of the 1992 standard repair time.
In October 1995, management set an unprecedented turnaround requirement of ninety days for the receipt, flushing, pending acceptance, and shipment of thirty-eight RCS engines to the Kennedy Space Center. Between 1992 and September of 1995, only forty three engines had been processed through the WSTF facility. This challenge meant that the repair team would have to process almost the equivalent of the previous three years' throughput in 8.3% of the time. Add to this time constraint the additional obstacle of limited financial resources it became obvious a radical process change had to occur.
Background of Reengineering
In 1993, Hammer and Champy's book Reengineering the Corporation championed radical transformation of American corporate processes. Up to this point with Total Quality Management, benchmarking, and other incremental approaches American companies had tried to improve their competitive position within the world economy with less than spectacular results. Reengineering discarded those incremental approaches and instead called for innovative change. Corporations were asked to re-identify themselves by their processes and not by functional organizational structures. Concepts were borrowed from incremental improvement approaches - putting the customer first, using teams, empowering workers, rewarding performance, and tearing down divisional walls. These concepts were then used as tools in a top-down, management-driven, business redesign. Hammer and Champy originally envisioned reengineering as only applying to corporations and preached their message to large corporations looking for a way to stay competitive in a world market. The Component Test Facility (CTF) at WSTF was not a large corporation but it applied reengineering to make the required radical changes in its new process design.
Hammer and Champy identified several key features in process reengineering. The first step toward changing the process was to correctly identify the process. CTF personnel performed this step by: 1 ) flow charting the process and performing a time study on the individual elements; 2) identifying the personnel and facility requirements for each element; 3) performing a work flow analysis; and 4) reviewing the process requirements (see Table 1).
|CTF Process Analysis||Description|
|Flow charting and time study||The flushing process was flow-charted and a cycle time was established for each major segment.|
|Identifying the personnel requirements||The job classification and the amount of required labor hours was determined for each step. The over and under utilization of personnel classifications were evaluated using this analysis.|
|Identifying the facility requirements by process stage.||Facility requirements, e.g., clean room, flush bench, etc., were identified to evaluate bottle necks and any potential areas where additional facilities were needed to meet the growing work load|
|Performing a work flow analysis||This evaluation identified the work flow from work station to work station within the facility.|
|Performing a review of the repair process requirements.||It was assumed that the repair process was set due to the rigid flight certification process|
Four reengineering opportunities emerged: 1) facility utilization and layout; 2) personnel roles and fixations; 3) development and tracking of procedures; and 4) the repair process itself. This section documents the reengineering efforts in each of the four areas.
The facility originally had been designed to process only a small number of engines. The facility layout had been dictated more by proximity to fluid sources than work flow. The analysis showed that the number of flush benches, the dirty work areas and the flow benches would need to be expanded to handle the new work load. Table 2 shows the various work areas used.
|Type of Work Area Used||% of Usage|
|"Dirty" - Visually clean work area used for testing, receiving and packaging.||34|
|Clean Work Area - Flow benches used for inspections, Pc tube flushing and Dynatube polishing, cleanser.||15|
|Flush Bench - Water and gas facility used for flushing, acceptance testing and leak tests.||24|
|Fume Hood - Decontamination.||7|
|External - Facilities outside of the CTF, vacuum chambers, x ray.||20|
An adjacent room was added to the facility. That new room was used as a pre-flushing staging area. Two new flow benches and an additional "dirty" work area were moved in. The fume hoods and the safety shower required for decontamination were relocated in the new room. A second flush bench and ante room were added to the existing facility.
Work teams consisted of a test conductor, mechanical technicians, electrical technicians and quality assurance personnel. Previously, the demand for engines allowed one crew to repair the engines in serial. This provided plenty of time between units for the test conductor to catch up on paperwork, facility work and reports. The test conductor oversaw the testing while concurrently performing the required paperwork and coordination with outside support. Also, the test conductor signed-off on each step of the procedure that each technician performed. This system was adequate if only one engine was processed at a time thus allowing the test conductor and the technicians to work side by side. With the increase in the number of engines this system was no longer possible. The new repair operation required an average of five engines to be in process at a time. With that many engines, the test conductor could not observe and verify every step.
The role of the test conductor was evaluated. The test conductor position was redefined from a direct supervisor, monitoring technicians' actions to an overall repair manager directing a corps of technicians and an engineering aide. Technicians were empowered to be responsible for their own work and were allowed to verify completion of the operation's steps.
Historically, the test engineer was the author of the site test procedures. This worked well since the test engineer was most familiar with the test and the test system. Under this system the paperwork was often written for an engineer and not a technician that was performing the work. This worked well in a test situation, (which constitutes 80% of WSTF's work), because the test engineer was able to monitor the steps of the procedure. In the repair area, with the proposed technicians' new responsibilities, the paperwork needed to become more technician friendly".
The procedures were changed by:
Placing all of the requirements for problem reporting, contamination and configuration control into a single requirements document rather than each procedure.
Breaking out major repair sections into smaller instructions. For example, the dock to dock all in one procedure was replaced with a receiving and inspection, a flush, a leak check, and several other procedures.
Rewriting the sections and adding diagrams so that system setups were easily followed.
Changing the tracking paperwork. A router to track and document the work was developed. In the old paperwork system, when a new engine entered the process a unique set of procedures was prepared for the engines. The complete flushing procedure was over 250 pages long. This method did provide a receipt-to-delivery record of the work performed on the unit and traceability to the technician who performed it. yet quality assurance personnel, technicians, test conductors and data clerks had the burden of preparing, maintaining, and archiving the voluminous amount of paper. The new router provided the traceability and permanent record of the work.
The new documentation format provided the following benefits:
The process requirements, similar to the procedural format, were a cumulative effort based upon years of flush development and requirements mandated through the direction of three different NASA managers.
Leak Checks An analysis of the history of a process' development is as important as the study of the process itself. During the analysis, it became clear that three of the leak checks - the initial, the interim and the post 20 hour leak check - were by-products of the flushing process development. With a mature process only the final leak check to accept the engine's performance was required
Dynatube Polishing The valves mounted on the engines have dynatube fitting inlets. Due to connection and disconnection and handling at Kennedy Space Center and WSTF, these dynatube sealing surfaces become scratched. The scratches provided leak paths and needed to be maintained to a specific surface finish. A dynatube polishing procedure is performed to refinish dynatube surfaces that have become scratched. Dynatube polishing was an extremely time consuming effort that may consume up to ten hours of mechanical technician time. This procedure was performed twice, when the engine was received, and prior to shipment. The process was changed to only polish the dynatube inlets once prior to shipment.
Pc Tube Flushing Previous to the analysis, Pc tube flushing had been performed in a Class 100 flow bench. During the process analysis it was discovered that the sole reason for this was the nitrogen source that was located by the flow bench. There were no costly clean facility requirements for this process. A Pc tube flushing station was created by locating a nitrogen source by the added work bench. The analysis also revealed that the pumps used to flush the Pc tubes were extremely slow. It was taking on average six to eight hours and sometimes 16 hours to flush a Pc tube. A different pump was purchased that performed the flush more efficiently.
The reengineering project invigorated the engineering team to reevaluate all processes. This ongoing review included evaluating the numbers of flushes, the pressures used during the flush, the type of flushing fluid, and the use of gaseous nitrogen to agitate the fluid.
The biggest benefit of the reengineering project was the new attitude toward change that was created. Prior to the project, change was viewed with suspicion. After seeing the effect of the improvements the work teams were more willing to evaluate, innovate and improve their processes.
A second benefit was the realization that understanding the process is important. Prior to the evaluation, the Component Test Facility repair processes had never been analyzed. The repair team had rough estimates of the length of the processing time but the effort was never made to measure and outline the process. Work flows or facility usage had never been evaluated or measured. By taking the time to perform the analysis, key areas for change were identified and the analysis provided the needed justification to management for the changes.
Overall, the changes made in the facility and process would not have occurred without management providing the initial goals and supporting the process changes. Every time a presentation was made to WSTF management, the general feeling from the other engineers was, 'they aren't going to buy into that'. But they did, and they encouraged and backed the new ideas. With the changes, total processing time for an average flushed RCS engine is now 84 hours instead of 142 hours. The amount of paperwork generated for a flushing operations was 12 pages after the change versus 250 pages prior to it. One test engineer was able to handle the paperwork and monitor the operations of two full crews. And, more improvements were being evaluated. That in itself may be the true sign of success for reengineering effort.
"We would like to thank the NASA White Sands Test Facility for their participation in this study. Thanks are also due to Linda Ann Riley for her comments on an earlier version of this article."
Hammer, Michael and Champy, James (1993). Reengineering the Corporation, New York: Harper Business.