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Lean principles contribute to success of Propulsion Replacement Program

HILL AIR FORCE BASE, Utah -- The 309th Missile Maintenance Group completed assembly of Minuteman booster No. 75-939 Nov. 7, marking two years of early or on-time deliveries by the unit.

The unit has maintained its completion and delivery record by using Lean principles, which helped organize work areas and remove waste from production processes.

Coincidentally, the date also marked the 309th missile completed by the 309th MMG and its squadrons, the 581st and 582nd Missile Maintenance Squadrons. The missile work is part of the Propulsion Replacement Program, a $2.4 billion project designed to replace outdated propulsion materials.

According to Dr. Yoon-Mi Hamrick, 582nd Missile Maintenance Squadron director, the Propulsion Replacement Program takes the missiles, whose solid propellant has passed its shelf life, out of the silos and replaces them with refurbished missiles expected to last until 2020.

"The missiles are brought to the depot, where we strip all the components off, separate them by stages and then deliver them to ATK Launch Systems for processing at the Bacchus plant or the Promontory facility," Mr. Hamrick said. "The contractor reams out the old propellant from the motor, and casts new propellant. We transport them back to the depot, assemble them into functional ICBM boosters and deliver them back to the warfighter."

Missiles that once spent two weeks in the assembly process are now completed in about six days. The crews produce eight Propulsion Replacement Program missiles per month. As of Nov. 7, crews have completed and delivered 185 missiles.

Depending on the availability of facilities, 4-6 missiles are in various stage of work at one time.

"It is a major undertaking that involves about 150 people such as missile truck drivers, disassembly and assembly crews, flight control mechanics, and cable and electronics technicians all working together to meet each customer due date," said Ms Hamrick.

"On a big logistics effort like this, you need to have everything in line and ready to go," she continued. "One of the big things we did to be more efficient was establish a control room to direct the movement of missiles, line crews, preposition parts and subcomponents, etc. The status of all activities is updated daily. Anything that is preventing the full usability of an assembly building such as equipment calibration, or a facility issue like a leaking roof is heavily scrutinized and promptly fixed. The control room report also has all facts in one concise report allowing managers to forecast possible delays then fix them before they happen."

To thwart one possible delay, extra parts and subcomponents for each missile were secured to create assembly kits. This ensures there would be no delays in missile assembly in case deliveries from the field are delayed by weather or other factors.

Daily coordination meetings with the 526th ICBM Systems Wing as well as a Five M review -- which includes material, manpower, metrics, measurement and machinery -- help anticipate and resolve problems.

Col. Robert Shofner, 526th ICBM Systems Wing commander, said the most important message is about what teamwork can accomplish.

"PRP is a success story about communication and partnership between industry, the systems wing, the depot, and the user," Colonel Shofner said. "If one of those team members fails it all comes crashing down around us.

"Two years of on-time deliveries is significant because it demonstrates to the warfighter we've overcome some real challenges on this program," the colonel continued. "Twentieth Air Force's confidence in our team's ability to deliver on-time is a significant advantage because it allows them to effectively manage their most limited resource, the people who have to defend and maintain launch facilities."

Completed missiles are shipped to Minot AFB, N.D., Malmstrom AFB, Mont., and F.E. Warren AFB, Wyo. At its present production rate, Propulsion Replacement Program work on the missiles is expected to continue through June 2009.