Experts say that manufacturers are nowhere near maxing out on potential productivity gains. Plenty of productivity headroom remains available to manufacturers who, for example, transform push-oriented supply chains into more agile, demand-driven supply networks. Similar, as Managing Automation recently noted, although manufacturers have attempted over the past few years to apply lean and Six Sigma principles, "most have only scratched the surface of what can be achieved."

In fact, according to last year's American Machinist Benchmarking Survey, the most important tool that shops use for reducing cycle times is an organized operations approach for continuous improvement:

Top shops are twice as likely to use formal continuous improvement programs — 51 percent of the top shops have formal programs in place compared with 27.4 percent of all other shops. Additionally, 88.2 percent of the top shops use lean manufacturing techniques, while half that number — 41.1 percent — of all other shops do. Reduced cycle times are a result of those programs.

Another recent American Machinist survey of machine shops found that almost all of the shops interviewed use practices common to lean manufacturing to make the transition from long to short production runs. (Most of them, however, do not use the normal lean manufacturing terms.)

Some of the most common techniques used to reduce cycle times involve CAM and other software tools that optimize toolpaths and maximize cutting time, according to respondents to the most recent survey. In fact, of the top shops, 96.1 percent use CAM packages, while 81.4 percent of the other shops do, and 47.1 percent of top shops use proprietary software tools compared with only 18.4 percent of other shops. "Offline toolpath optimization and verification offer substantial improvements in this area," recently wrote American Machinist's Larry Haftl.

More than 76 percent of top shops try to maximize machine uptime compared to 36.7 percent of the other shops.

The types of equipment that shops use may vary from manual machines to the latest CNC machines. The oldest machine in one shop could be only a few years old, and the newest machine in another shop may already have a decade behind it.

Regardless of machine type and age, all companies should pay close attention to the equipment's effectiveness — which directly affects production, uptime/downtime, slow cycles and defects.

Think about all of the categories of maintenance issues that can easily turn into productivity issues: unexpected breakdown losses; set-up and adjustment losses; stoppage losses; speed losses; quality defect losses, in which defects lead to reworking or scrapping; and equipment losses from wear-and-tear on equipment, reducing its durability and productive lifespan.

When it comes to equipment, on the shop floor and beyond, organizations typically pursue four techniques for Total Productive Maintenance (TPM): efficient equipment, effective maintenance, mistake proofing (known as poka-yoke in lean contexts), and safety management.

The best way to increase equipment efficiency is to identify losses that are hindering performance. Overall Equipment Effectiveness (OEE) has become something of a hot issue for many manufacturers. It provides an easier way to "keep score" of manufacturing performance — "from a single piece of equipment to an entire manufacturing plant" — as Vorne Industries president Ramone Vorne and electrical engineer James Feltman recently wrote at Manufacturing.Net. Moreover, it is a tool for continuous improvement and lean manufacturing initiatives.

Thorough and routine maintenance is a critical aspect of TPM. Equipment operators are trained to play a key role in preventive maintenance by carrying out "autonomous maintenance" on a daily basis by way of precision checks, lubrication, parts replacement, simple repairs and abnormality detection. Workers are also encouraged to perform corrective maintenance, designed to keep equipment from further breaking down, and to facilitate inspection, repair and use. (One of the most important principles for improving OEE is to extend accountability all the way to the floor, which instills a sense of ownership to the frontline employees, according to Vorne and Feltman. However, some companies find that OEE is a bit abstract for the plant floor, and while they track OEE for various reporting and management purposes, they prefer to focus on simpler metrics for plant-floor employees.)

Mistake proofing is the application of simple "fail-safe" mechanisms designed to make mistakes impossible or at least easy to detect and correct. A prevention device is one that makes it impossible for a machine operator to make a mistake. A detection device signals the user when a mistake has been made; this way the user can quickly correct the problem.

Like maintenance, safety activities under TPM are to be carried out continuously and systematically. Focus areas include the following: development of safety checklists; standardizations of operations; and coordinating non-repetitive maintenance tasks.

The dual goals of TPM are zero breakdowns and zero defects; as implied, this improves equipment efficiency rates and reduces costs. It is determined that most companies can realize a 15 percent to 25 percent increase in equipment efficiency rates within three years of adopting TPM, according to Superfactory. "Labor productivity also generally increases by a significant margin, sometimes as high as 40 percent to 50 percent."

Elsewhere in the realm of equipment on the floor, the use of automation and robotics can also maximize total throughput on a production system. Of the top shops in American Machinist's survey, 43.1 percent said they use automation, compared with only 21.2 percent of the other shops. Further, 27.5 percent of the top shops use robotics, but only 11.9 percent of other shops do.

In the end, it all comes back to the most important tool — a program and commitment to continually improve the total production process. Cycle times certainly need to be considered, but cycle time improvement without overall production process improvement will not improve a business's bottom line.

Remember: Lost production time — including every hour a machine is not functioning optimally — is lost forever.

For key indicators/steps that a machine shop can take to make improvements, also visit American Machinist's "How Do You Measure Up?" from fall 2006.

Earlier: Machine Medicine: Improve Your Maintenance Program in 10 Steps

Resources

Redefining Manufacturing Productivity
by Jeff Moad
Managing Automation, Nov. 20, 2006

How Best Shops Reduce Cycle Times
by Larry Haftl
American Machinist, Jan. 24, 2007

Top Shop Analysis: Best Shop Tools
by Larry Haftl
American Machinist, July 5, 2006

The ABC's Of Overall Equipment Effectiveness
by Ramon A. Vorne and James A. Feltman
Manufacturing.Net, Jan. 30, 2007

Superfactory: Total Productive Maintenance (TPM)