Not content to rest on its laurels after opening the first concrete plant designed for U.S. Green Building Council's Leadership in Energy and Environmental Design certification (see Concrete Products, April 2003, “Taking the Leed”), Castcon-Stone Inc. has begun implementation of a Lean Manufacturing protocol. The Saxonburg, Pa.-based precast stair producer is taking cues from heavy hitters like Toyota Motor Co., one of the most prominent users of Lean Manufacturing, to optimize operations at its new 47,000-sq.-ft. facility.

“People think the process applies mainly to manufacturing widgets,” notes Castcon President Laura Huch-Kerckhoff, “but we see many potential benefits in a concrete plant setting.” Though Tindall Corp.'s Petersburg, Va., facility and High Concrete Structures' plant in Lancaster, Pa., follow the protocol, Castcon is pioneering the first companywide application of Lean Manufacturing among concrete producers. “The advantage of our size,” says Huck-Kerckhoff, “is that we can readily implement the system throughout the entire organization.”

Hiring James Clark to fill the newly created position of chief operating officer marked the beginning of Castcon's deployment of new production strategies. Under his direction, a Lean Manufacturing workplace will be established on the basis of a program of organization and cleaning whose benefits are said to include greater safety, higher productivity, fewer product defects, maximum efficiency and timeliness at lower cost. The initial phase of this paradigm shift is nearing completion, contributing to a 22 percent sales increase in the fiscal year ending May 1 and an anticipated further gain of 15-20 percent this year.

According to Clark, any manufacturing environment, especially a ‘green’ facility like Castcon, is challenged to make better use of labor and materials. Applying the 5S principles — sort, set in order, shine, standardize, and sustain — that comprise the foundation of Lean Manufacturing, the facility was able to regain two 35-ft.-wide × 18-ft.-deep mezzanines previously filled with primarily disposable materials. One of those areas is now used to prepare metal nosings for stairs; the other will be dedicated to an expanded quality program.

Modifying the plant layout to optimize efficiency also involved the addition of stair form stations, bringing the total to eight, plus four to five platform areas. Concurrently, forms on axles were placed instead on stable legs, as overhead crane equipment made greater mobility superfluous. Reconfiguring the entire plant floor as needed is still easily accomplished, Huch-Kerckhoff observes.

Another measure facilitating ‘quick changeover’ or single-minute exchange of dies (SMED) is the replacement of 6-ft.-long × 7-ft.-high workbenches at each station with mobile tool carts. After the prototype currently in use is refined, a cart will be provided for each stair builder to transport tools and supplies. The flexibility and time savings thus gained reportedly reduce many tasks from hours to minutes.

Production Teams also contribute to greater efficiencies on the plant floor. Assigning a team to multiple forms and allowing its members to coordinate production activities reduces work time dramatically. This impact is especially evident in minimizing nonvalue time involved in setting up a stair form: the time required to travel the 85-ft. circumference of a 35-ft. × 7-ft. form is halved when a two-person team tackles the job. Like a NASCAR pit crew, says Huch-Kerckhoff, a team can better examine the condition of forms and prepare them for production, thereby contributing to quality and efficiency. Accordingly, Clark affirms, “Quality is owned by the production people.” Builders are expected to make the part correctly the first time and to stop the process immediately if a problem arises.

Work flow is further supported by a change in management structure. Team leaders now replace floor supervisors. A newly reorganized quality department is headed by a skilled manager whose experience allows him to oversee both quality and project management functions. A new manager has joined the project management staff, and a quality technician will soon be added to provide a testing specialty in the quality control department.

“Our quality and project manager is passionate about mix design to meet and exceed customer and worker expectations,” says Clark. For improved workability and high performance, especially for transit-project mixes, he is supervising the examination of various admixtures and cementitious materials, including ground granulated blast-furnace slag (GGBS), silica fume, and pozzolans. A thorough exploration of options will determine conventional and self-consolidating concrete mix designs.

In addition to plant layout, point-of-use storage, formwork, team effort, and mix design, a significant component of Castcon's Lean Manufacturing program is employee feedback. Instituting a formal procedure to handle employee suggestions involves garnering ideas, tracking results, and setting timetables for issues to be addressed by appropriate teams. “When people see that their suggestions are taken seriously, they are far more likely to submit ideas,” contends Huck-Kerckhoff. “Since establishing formal channels for employee input, we have implemented many excellent suggestions, especially with respect to storage and yard management.”

Clark emphasizes that Lean Manufacturing is a tool — a means, not an end — to remove the roadblocks to measurably greater productivity and higher quality. “In our mission to provide quality, value, and service,” he asserts, “Lean Manufacturing enables us to be more efficient while putting the customer first.” Using SMED ‘quick changeover’ techniques to reduce form set-up time, for example, permits a cellular manufacturing approach by which “we can make what we need when we need it,” Clark notes. Such a protocol relieves storage pressures, eliminates handling goods more than once, and facilitates form maintenance.

Previously, in casting various components for a job, the highest possible number of pours was attempted with one form before changing to the next. As changover has been expedited, Castcon now casts components according to the customer's schedule. Huch-Kerckhoff explains, “A customer building a parking structure typically wants one stair tower produced at a time; masonry construction or a steel building requires stairs floor by floor. Now, we can accommodate those schedules rather than produce in bulk.” Especially as design-build construction becomes the norm, she continues, production flexibility is key, because securing a schedule at the outset for the entire project is increasingly difficult.

Also in response to customer feedback and market demand, Castcon is rolling out its latest offering — a total precast stair tower. Prospects for its use in construction of New York City's PATH underground station were recently discussed with officials of the Downtown Design Partnership, consultants in Ground Zero redevelopment. High rises, apartment buildings, and municipal structures are likewise seen as promising applications for the stair system.

Yet, Huck-Kerckhoff avers, “We're just at the tip of the iceberg in becoming more adaptable and efficient.” Adds Clark, “We have implemented only the initial phase of a paradigm shift, which says ‘We can do better.’”

Further demonstrating that commitment to ongoing development, Castcon is partnering with the University of Pittsburgh's Civil Engineering Department to substantiate by means of quantitative analysis the anecdotal evidence of ‘green’ building benefits. Through 2009, the project will examine and measure productivity gains, employee perceptions, and energy savings related to ‘green’ construction. Clearly, as Clark maintains, ‘Lean and green’ is “not a destination — it's a journey.”

LEAN ORIGINS

Early attempts to boost company profits by implementing strategies to improve output, reduce costs and increase market share can be traced as far back as Eli Whitney and Henry Ford. Subsequently, Japanese manufacturers rebuilding after World War II were challenged by a drastically reduced workforce, limited raw materials, and little money — conditions that led to the development of ‘lean’ practices, known then as “just-in-time” manufacturing. Japanese business leaders like Toyota Motor Co.'s Eiji Toyoda, Taiichi Ohno, and Shingeo Shingo implemented a disciplined, focused production process incorporating Ford's assembly line, Statistical Process Control, and other techniques to minimize resource expenditures that add no value to the end product.

Following the 1990 publication of James Womack's “The Machine That Changed The World” — a straightforward account of the history of automobile manufacturing including an examination of Japanese, American, and European automotive assembly plants — Massachusetts Institute of Technology undertook a formal study of the mass-production process described in the book. Thus, given further credibility by a renowned academic institution, the Lean Manufacturing theory gained widespread popularity in American factories and continues to set the standard for mass production.