Time is Money
AbstractHow many times have you heard from your parents: "Clean up your room!" or "Don't forget to unload the dishwasher!" By applying principles of industrial engineering and time management, you can speed through your chores and have more time to kick back and relax.
Michelle Maranowski, PhD, Science Buddies
This project is about efficiency and successfully completing a task. You will create a process flow to accomplish a task (like emptying a dishwasher) accurately, in as little time as possible, and with a minimum of mistakes.
Industrial engineering is a branch of engineering that involves the development, improvement, and implementation of integrated systems of people, equipment, energy, material and process; in other words, evaluating and improving how things work together (Wikipedia contributors, 2007). Industrial engineering utilizes the principles and methods of engineering analysis, as well as mathematical, physical, and social sciences. Using these tools, an engineer can solve complex problems involving different systems that must work together. The goal of industrial engineers is ultimately to save time, money, materials, energy, and other resources, in addition to improving quality and productivity of various systems.
Topics that industrial engineers study include: motion and time, ergonomics, machine capacity, material flow, and material quality. Industrial engineering is used in many areas of business, including the health care, automobile, and semiconductor industries. Ergonomics (the study of how humans interact with tools and their environment) is of great concern to manufacturing companies because of the time that is lost due to worker injuries and fatigue. Injuries and fatigue can happen when a tool or process is not properly designed for human use.
In this project, become an industrial engineer! Take an everyday process, like loading and unloading a dishwasher, and improve it. This project mimics developing a process flow in a manufacturing plant. In all processes there are steps that are performed over and over again. The process must be designed around these steps to minimize wasted time and maximize efficiency. In this project, the dishwasher is the rate-limiting step, or bottleneck. You will create a process flow for loading and unloading. Remember, time saved can be spent doing fun stuff!
Terms and Concepts
- Industrial engineering
- Motion and time study
- Process or process flow: a list of instructions or actions
- Operations research
- Quality control
- How long does it take to move the dishes from the table and load them into the dishwasher?
- How long does it take to unload the dishes from the dishwasher and place them back in their correct locations in the cabinets?
- What kind of motions does a human make to load and unload a dishwasher?
- What kind of tools can be used to improve upon the time it takes to do the task?
- What methods (labor, technique, etc.) can be optimized to minimize the time required for dishwasher loading and unloading.
- Is there a relationship between how the dishwasher is loaded and the cleanliness of the dishes? Calculate yield and throughput.
- Learn how some of these industrial engineering concepts were developed by time-management pioneers Frank and Lillian Gilbreth. The
Gilbreths wanted to find the "best way" to tackle a task:
Gilbreth, F. B. and Carey, E. G. Cheaper by the Dozen. New York: Harper Collins, 2005.
- Check the technical resources on the Institute of Industrial Engineers website for illustrative case studies, terminology, and links:
IISE. (2007). IE Body of Knowledge. Institute of Industrial & Systems Engineers. Retrieved December 17, 2007.
- Wikipedia contributors. (2007). Industrial Engineering. Wikipedia, The Free Encyclopedia. Retrieved December 17, 2007.
- Wikipedia contributors. (2007). Therblig. Wikipedia, The Free Encyclopedia. Retrieved December 17, 2007.
Materials and Equipment
- Lab notebook
- Make sure that your dishwasher is empty and ready to be loaded and that you have about the same number of dishes to clean during each trial.
The full process is defined as loading the dishwasher, the cleaning cycle, unloading the dishwasher, and then putting the dishes away. Separate the full process into three segments: the loading process, the cleaning cycle, and the unloading process. The unloading process includes putting the dishes away. In order to make lasting improvements to the full process, you will need to study and time each segment at least three times. Be sure to record your results in your lab notebook at the end of each trial, using a data table like the one below.
Trial 1 Trial 2 Trial 3 Trial 4 Number of dishes to be cleaned Time to load Number of broken dishes during load Time for dishwasher to run Time to unload Number of broken dishes during unload Number of poorly cleaned dishes Process time (the total time it takes to load, clean, and unload the dishes) Yield (the number of clean dishes, divided by the number of dishes to be cleaned.) Throughput (the number of clean dishes, divided by the process time.)
Loading and Cleaning
- Start timing the loading process as soon as you move the first item into the dishwasher.
- Stop timing the loading process once all of the dishes are loaded and the dishwasher door is shut. Be sure to load as quickly as possible, but not so fast that you risk breaking dishes. One of the goals is to be as methodical and scientific about this as possible, and breaking dishes wastes money and resources, which goes against industrial engineering principles. However, if you do accidentally break any dishes, it is important to record that in your data table.
- Once the dishwasher has been loaded, start the clean cycle. Time the clean cycle.
- Do the loading process at least three different times in order to understand the motions a human makes to load the dishwasher.
- After observing the loading process several times, see if there are steps that can be changed to minimize the loading process time. Apply the changes and then time the new loading process. Note any improvements or if the process led to worse results. Remember, try to minimize the number of broken dishes and maximize cleanliness. Be sure to time the new loading process at least three different times.
- Now observe the unloading process. Make sure that the dishwasher is ready to be unloaded.
- Start timing the unloading process as soon as you open the door to the dishwasher.
- Stop timing the unloading process once the dishes have all been put away in their correct locations. Make sure to count the number of broken items and the number of dishes that are not clean.
- Do the unloading process at least three different times in order to understand the motions a human makes to unload the dishwasher.
- After observing the unloading process several times, see if there are any steps that can be changed to minimize the unloading process time. Apply the changes and then time the new unloading process. Note any improvements or if the process led to worse results. Try to minimize the number of broken dishes.
- Analyze your data. Remember to take into account the number of clean and unbroken dishes and the number of dirty and/or broken dishes into your analysis. Calculate yield and throughput. Yield is the number of clean dishes, divided by the number of dishes to be cleaned. Throughput is the number of clean dishes, divided by the process time. The process time is the total time it takes to load, clean, and unload the dishes.
- While industrial engineers are concerned with reducing the time it takes to complete a process, time is not always the most important variable. Improving processes sometimes means reducing breakage and waste. If it's ok with your parents, try using plastic dishes and plastic glasses instead of ceramic or glass. This may reduce breakage. Also, try using a cart to move dirty and clean dishes around. There are many ways to improve a process.
Ask an Expert
- Add another worker and see if the process improves or gets worse.
- Apply the principles you have learned to other processes in your house.
If you like this project, you might enjoy exploring these related careers: