The Waste of Waiting

Lean Don't Wait

So far we have talked about waste in the forms of overproduction, inventory, motion and over-processing. By now, I'm sure you would agree that finding waste is much more than looking for lazy people who spend an extra five minutes on break on Friday afternoons.

Waste is insidious. It can lurk within things that frequently look to be good or positive for the overall process. Frequently what looks good at one point of the process is wholly at the expense of production at another point in the process. This time around, we are going to look at the wastes of waiting and of conveyance or unnecessary movement.

The Waste of Waiting

"Hesitation Blues" tells a story of the frustration associated with unrequited love or at least resulting from misaligned goals. The fellow in the song suffers an endless wait because the target of his affection has other priorities. He must wait!

Waiting is one of the key types of waste. Waiting occurs when material in process (or WIP, Work in Process) is not moving through the production process. Workstation personnel are idle, waiting for work. You're on station, your parts inventory is ready, and your tools are primed for action; there's just nothing to do. So, you wait. If this is a five-minute, once-a-month event, it's not so bad. If it happens continually, it is extremely wasteful.

The minutes spent waiting add up to hours, the hours compound themselves into weeks, and soon the weeks are extending over multiple months of time spent in complete inactivity.

If you ever had the pleasure of experiencing the fun of "boot camp" or the culture of the military in the larger sense, you are familiar with the term "hurry up and wait."

During my own early days at the Naval Training Center in San Diego, CA, our Company Commander would run us from one end of the base to the other, all the while screaming and ranting about how we were all worms, squirrels and cockroaches.

We would run to the barber shop so we could lose our glorious long locks, then we would run to the outfitters where we were issued our ill-fitting uniforms and sea bags. Following that, we ran to the dispensary for our daily round of shots and inoculations. The only fun part was running to the galley where we were given 20 minutes to eat.

Every day we would run, run, run and then we would wait. At each destination, we would wait for our paperwork to catch up, wait for our medical records to be pulled or wait for the appropriate personnel to show up and do whatever it was they were supposed to do to us. Eventually, we got our cue-ball haircuts, our too-small uniforms or our daily ration of Jungle Rot vaccine. But, we always had to wait first.

In the world of manufacturing, waiting occurs within the assembly process because of an imbalance in the flow of materials through that process. Each station has a throughput capability. One manufacturing process may require 30 minutes to process a single unit while another requires 10 minutes and yet another requires a full hour.

This disparity in processing time causes Work in Process (WIP) to back up at some points during the process, which in turn causes down-line processes to wait on work. This is made worse in linear processes where each successive process depends on completion of the previous process.

The goal is to synchronize the production process to match customer demand. This, in turn, facilitates a steady, even production of product with no bottlenecks along the way. No one waits on product and no one is overwhelmed trying to keep up with demand for product.

The first step in this process is to establish the Takt time. This is taken from a German word, taktzeit. Taktzeit translates roughly to clock cycle or time cycle. In manufacturing, the desire is to establish a steady, minimally fluctuating production pace. This is almost like the heartbeat or pulse rate of the production process

Takt time is calculated by dividing available production time by demand. If your plant operates on eight-hour shifts and your demand per shift is eight units, the resulting takt time is one hour. If your demand is rated at 16 units, your takt time is 30 minutes.

The takt time is used to tailor your production process, making resources available and capacity adjusted to match, as closely as possible, the established takt time.

An examination of your production processes will reveal the assorted throughput capabilities of each sub-process or workstation. Some of these will exceed the takt time requirement and others will fail to produce sufficient volume to keep up with demand.

If Station A is throughputting 100 units per hour, and Station B is only able to handle 50 units per hour, there are two things that can be done. You can reduce resources available at Station A thus cutting the production to match Station B. By the same token, you can add resources to Station B bringing the throughput there up to that of Station A. Takt time tells you which of these two options is the most desirable.

By organizing your production processes into work cells, you can make your overall production process more responsive to changes in customer demand. Work cells combine multiple assembly or processing steps into a single unit. Each unit is balanced in terms of takt time and throughput. As demand fluctuates, cells are added or taken away to meet changing demand needs.

This facilitates a steady amount of work distributed evenly over the entire production process that minimizes backlogs, bottlenecks and downstream waiting.

If we pay a short visit to our hamburger stand, we can see ample evidence of this as well. The number of people flipping burgers, dropping fries and taking orders is widely variable between noon and 3:00 p.m. The number of customers is also variable. At noon, you will see 20 customers waiting in five lines. There will be five cashier/order takers, three burger cooks and two fry cooks making sure the orders are processed quickly. Each customer is waiting no longer than three minutes from the time they step into line to picking up their bag of goodies and heading for a table.

At 3:00 p.m., the scene changes. Four customers wait in a single line, one cashier is taking orders and one guy is in the back cooking burgers and making fries. But even though overall demand is reduced to 20% of the peak demand experienced at noon, the customer is provided with the same level of service as are the lunch patrons ... fresh burgers and hot fries in about three minutes.

The Waste of Conveyance

Conveyance, as the name implies, has to do with wasteful transportation, storage or handling of items in the production process.

We have a restaurant chain in our area that features the one-price, all-you-can-eat, multiple-station buffet concept. I'm sure you've seen these places. You move through a little maze of chrome fences designed to regulate the unending tide of humanity flowing toward the cashier station. You pay in advance and after making payment, you are given a set of flatware and a rather small plate.

After that, you are allowed to enter into the serving area or as I like to call it, Hog Heaven. This is a place that gourmands of the world probably fantasize and dream about. There are numerous kiosks, each one featuring different foods. These are organized based on cooking process, food group, ethnicity and time of day along with several other defining factors.

You will have a pancake, omelet and waffle bar. There will be steak, prime rib and roast beef counters. There is usually a pasta bar that also serves pizza. Our Hog Heaven features separate stations for fried chicken, hamburgers, baked potatoes, assorted salads, vegetables (not too many vegetables) and of course, desserts—lot’s of desserts.

The real action is not so much the food itself, but rather the patrons. These people fully understand the waste of conveyance. Their little plates are stacked with food. The goal is to limit the number of calorie-wasting trips through the serving area by piling as much food as is possible onto the little plate.

You will see plates with a nice bed of pancakes supporting a porterhouse steak that serves as a foundation for several slices of pizza held in place by a mountain of mashed potatoes containing a crater of tomato soup. Lying on top of the potato mountain will be a slice of apple pie and a side of baby-back ribs. A glorious crown of chocolate ice cream, dream-whip and maraschino cherries tops everything off. Any empty areas between the various courses of the meal are filled with Jello salad that doubles as a kind of cement to hold the whole thing together.

The now drooling patron will head for the nearest available table comfortable in the knowledge that further physical activity will be limited to lifting a fork and a large glass of lemonade. Additional energy-depleting trips will not be necessary because the 5,000-calorie, self-serve banquet crowded onto the single little plate will satisfy even the most massive appetite.

Unnecessary conveyance on the factory floor is not quite so humorous. The unnecessary transportation of work in process, people and/or machines involved in the manufacturing process or of parts and supplies can add up to a devastatingly large hidden cost. Elimination of this sort of waste can be as simple as redesigning the work space or layout of the shop floor.

On some occasions, this can be less obvious involving practices left over from previous requirements. There are also situations where some individuals feel compelled to involve themselves in approval or checking cycles out of ego or the need to assert their own usefulness to the overall process.

This can be reduced through the Kaizen practice of continuous improvement. Constant review and evaluation of all processes will identify this type of wasteful practice.

Next time around we will wrap up this series on types of waste. Our last installment will deal with the waste of defects. As more and more businesses become quality centered, if not obsessed, defects are the single area where everyone wants to see improvements.

How About You?

I would love to hear from you about your own battles in uncovering waste. Drop me a line, and I'll put your name in a hat to win one of our new Cincomic Books autographed by our famous cartoonist, Tom Hortel!

About the Author:

Lou Washington Bio: I started my career in information management from the somewhat misunderstood field of Records Management. Following four years of working for the University of Missouri System's Office of Records Management, I joined Tab Products Co. in 1980. Shortly thereafter, I became interested in the software business, PCs and how those systems would shape the enterprise of the future. We were transferred to Tab's then corporate HQ in Palo Alto, CA where I was in charge of Tab's North American conversion operations. I became the first Product Manager for Tab's Tracker systems software products that utilized a PC-based bar-coding system to track the movements of everything from files to capital assets. I believe it was the earliest example of workflow automation available on the market. I was also peripherally involved in Tab's Laser Optics division, which brought to market one of the earliest business systems employing CD-ROM and WORM technology as an information storage media.

In 1990, I returned to Cincinnati and joined Cincom Systems where I began to learn about and work with mainframe-oriented products and systems. In those days, there was a real "split" between the mainframe forces and the desktop proponents. I always found this to be amusing since both had so many positive things to offer an enterprise. I could never understand why anyone would offer one at the exclusion of the other.

My role at Cincom soon expanded to include a number of things including product security, pricing, finance packaging and industry research.

Contact Information:

Lou Washington