1. Quality Management and Statistical Analysis (MGMT 580)
By Daren Krier
February 15, 2015

2. Case Study 3.1 Introduction
WP Inc. manufactures small metal parts
Create tools, stamps, bends, and forms based on customer design
Deburr parts
Wash parts
Ship product to customer
WP Inc. manufactures small metal parts for their customers based on a design given to them by their customer. The process is made up of four major steps. First, creating tools necessary to manufacture the product, which is the value added process WP Inc. wants to outperform their competition. The next step WP Inc. does to their product is deburr the parts. The third step is washing the parts to remove the oil, dirt, and metal pieces. The last process done at WP Inc. is shipping the product to the customer. Of all the processes completed at WP. Inc, the part washer has been the most troublesome. The nozzles in the part washer are becoming clogged up during part washing, causing a lengthy delay in the process, and potentially causing WP Inc. to miss deliveries to customers.

3. Process Flow Chart
Customer Order Received
Creation of tools/necessary components to make product ordered by customer
Customer Parts Manufactured
Tooling/Components designed to manufacture product
The process flow charts shows the sequence of actions necessary to fulfill a customer requirement. Once a customer purchase order is received, the engineers develop tools and other components necessary to manufacture the product. Once that step is completed, the tooling is used on the machines to manufacture the product, followed by the parts being deburred, and then moving to be part washed and shipped to the customer.
Parts are deburred
Parts washed in part washer/shipped to customer

4. Problem Statement
The part washer sprayers are being plugged up with a substance, causing parts to not be fully cleaned when ran in the part washer. Due to the parts not being washed completely the first time through the process, time is wasted unplugging the part washer sprayers and running the parts through the process a second time.

5. Brainstorming Employee variance Water temperature Chemical Reactions
Sprayers need replaced
Too big of pump, therefore pulling debris into the pipes
Parts debris (metal shavings) are too big, so part may need rinsed before being placed in washer.
Soap substance reacting incorrectly with water
Paint chips
FOD (foreign object debris)
Above are brainstorming ideas of what may be causing the sprayers to be plugged.

6. Quality Improvement Steps (DMAIC)
Plan
The problem within the process is the part washer sprayers are plugged with a substance, causing the parts to not be cleaned appropriately each time the part washer is used.
Quality improvement team will consist of an engineer, part washer operator, mechanic, and an outside observer within front office (i.e. Program Manager).
The improvement plan should decrease the number of times the part washer tank is emptied and cleaned, as well as prevent the sprayers from being plugged.

7. Quality Improvement Steps (DMAIC) Continued..
Plan (cont.)
Sprayers inside the part washer are becoming plugged, causing parts to not be washed correctly.
Possible Causes
Hard-water buildup
Calcium
Chips from the parts
Paint chips
Soap flakes
Something caused by a chemical reaction
Miscellaneous gravel or dirt (FOD)
The possible causes of the sprayers being clogged allow the quality team to develop a plan to study each one of those categories. Hard-water buildup is caused by “high levels of calcium, magnesium, and other alkaline minerals” are found in the water (Howell, 2013). Calcium within the nozzles will more than likely come from the hard-water as well. Chips from the parts may be the cause due to small metal shavings remaining on the part after the machine and deburr. Although paint chips seems unlikely, it is still a possible candidate the group will need to review. Soap flakes are possible due to the multiple times the tank is being emptied and refilled. A chemical reaction may be occurring when the water is heated, causing the soap to create small particles that plug the sprayers. Last, the quality team will check to see if FOD getting into the tank, causing the sprayers to be plugged.

8. Quality Improvement Steps (DMAIC) Continued (Current Process Flow Map)
New soap and water added to tank
Water is emptied
Yes No
Is water dirty?
Coils Heat Water No
Above is the current process for the part washing machine (Summers, 2010, p. 100). It helps draw a picture to show where certain areas for corrective action can take place in the future.
Are parts clean?
Part washer turned on
Dirty parts placed in machine
Parts Run
Move to next step
Yes
Evaporation occurs; water and soap are added

9. Quality Improvement Steps (DMAIC) Continued..Do
After review of all possible causes, it was determined the nozzles were being plugged with small particles of soap.
The tank is filled with soap particles on the bottom of the tank
Soap best dissolves at a high temperature
No filter system currently exist in system
After review of the potential causes, it was determined the substance inside the sprayers is small soap particles. When the water inside the tank is replaced, the bottom of the tank is not cleaned, and when new water is placed in the tank, the soap particles on the bottom of the tank are recycled through the tank. When the soap particles are floating through the tank, the pump is taking in the particles and plugging up the sprayers, causing parts to not be cleaned appropriately.

10. Quality Improvement Steps (DMAIC) Continued..
Do (Cont.)
WP Inc. will begin recording the temperature of water before part washer is ran, confirming water temperature is correct.
When the tank is drained, the bottom of the tank will be cleaned to remove soap debris once per week.
A filter system will be placed on the pump to remove debris from reaching the sprayers.
Preventative maintenance books will be used to record number of cleanings, which sprayers are plugged in the system, how much soap is used when refilling tank, and number of times part washer was used between each tank cleaning, etc.
The above actions will take place to help understand the processes necessary to make sure the sprayers do not plug up in the future. First, the temperature of the water will be recorded daily, and the parts will not be run until the temperature reaches the desired degree. Second, when the part washer tank is cleaned, the bottom of the tank will be cleaned once per week. Next, a filter system will be placed on the pump to prevent small debris from entering the pipes/hoses leading to the sprayers. Last, a preventative maintenance book will be placed near the machine to record all maintenance taking place on the machine. The book will record how often the machine is drained and refilled, how often the bottom is cleaned, how much soap is placed in the machine, when/which sprayers were plugged (hopefully sprayers will not be plugged due to corrective actions, but if they are plugged, it will be important to understand which sprayers are plugged), how often the new filter is replaced, and any other maintenance records necessary to keep the part washer running correctly.

11. Quality Improvement Steps (DMAIC) Continued..
Study and Act
The solution to the problem is to record water temperature, record maintenance issues in a preventative maintenance log, train employees, place filter on the pump, and clean the bottom of the tank on a regular basis.
The maintenance logs will need reviewed on a regular basis to make sure data is being recorded. To ensure quality of the product, a follow up meeting will be set 1 week from incorporation, and another follow up meeting 1 month after incorporation. If the new process is not working, the reevaluation process will restart and another new process developed
By capturing the data associated with the part washer maintenance, continuously improving the process will be easier because a history of the process will be recorded. Based on the history, WP Inc. can decide if they are cleaning the tank too often, not often enough, changing the filter too often, etc.

12. Hard-Water Buildup/Calcium
Cause and Effect Chart
Soap Flakes
Chemical Reaction
Gravel/Dirt (FOD)
Too much soap
Water too cold?
Operator FOD?
Hot water reduces reaction
Build up on bottom of tank
Plugged Sprayer
When first starting to develop a cause and effect chart for the reason of plugged sprayers, it was determined six issues may be causing the sprayers to be plugged. As shown above, the six issues each have a chance to get into the pump and cause issues with the sprayer.
Other debris on part
No water softener
Metal Shavings
Paint off part washer peeling
Hard-Water Buildup/Calcium
Chips from parts
Paint Chips

13. Force Field Analysis Driving Forces Restraining Forces
Run Product through part washer only once
Currently, no filters exist for pump
Increase # of cycles before part washer needs cleaned
Tools necessary to clean bottom of tank
Improve part quality after first run
Unfamiliar with new process
Actions
Record temperature of water when placing parts in washer
Install filter on pump to reduce debris in pipes
Clean bottom of tank weekly to remove excess soap
Record data in preventative maintenance logs
Employee training
The driving forces for improving the part washing machine is to improve the efficiency of the process. The goal is to run a part through the machine only once, increase the number of cycles before the part washer needs cleaned, and improve quality of the part being cleaned. The restraining forces are limited in this process because most of the necessary adjustments can easily be fixed, it just required training and data. The first restraining force is no filters currently exist for the pump, so a new pump with a filter may be necessary. Second, the employees may need new cleaning tools to clean the bottom of the tank. Last, employees are unfamiliar with the new process, so training will be necessary. The actions necessary to make the process more lean is recording the temperature of the water when the parts run in the machine, install a filter on the pump, clean the bottom of the tank on a regular basis, create a preventative maintenance log book, and employee training on the new process.

14. Management Summary Record date/time New soap and water added to tank
Water is emptied
Yes, check filter records/replace
Record amount of soap added/Clean bottom of tank 1/week No
Is water dirty?
Coils Heat Water
No, review maintenance log
The new process flow map shows the new steps necessary to understand the why the sprayers are being plugged up. By recording data in a preventative maintenance log book, WP Inc. can break down the necessary maintenance into daily, weekly, monthly, and yearly procedures. By understanding this data, it can be determined if different maintenance procedures need to take place more/less often. For example, with a new filter installed, it may not be necessary to change the water once per day, but maybe once per week. The bottom of the tank may not need cleaned once per week, but instead, once per month, therefore saving time and cost associated with cleaning the tank. The important part of the book is it will record all information for the part washer, allowing past data to be reviewed to continuously improve the process.
Are parts clean?
Part washer turned on
Dirty parts placed in machine
Parts Run
Move to next step
Check temp. of water
Yes, record data in log
Evaporation occurs; water and soap are added

15. References
Howell, E. (2013, March 25). What Makes Water Hard? Retrieved from
Summer, D. (2010). Quality (5th ed.). Upper Saddle River: Pearson Education, publishing as Prentice Hall.