1. Case Study 3.1: WP Inc. Problem-Solving
Group 2: Danny Taylor, Jason Thigpen, Susan Leuquire
MGMT 580 Quality Management & Statistical Analysis
Instructor: Ms. Connie Fleming
Southwestern College Professional Studies

2. Problem Statement
The spray nozzles of the automatic parts washer frequently clog with particles causing the parts washer to be shut down. This is unacceptable and delays every process in WP Inc. because every part manufactured goes through the parts washer.

3. List of Possible Particle Identities
Hard-water buildup
Calcium
Chips from the parts
Paint chips
Soap flakes
Result of a chemical reaction
Gravel or dirt
Corrosion or rust

4. List of Potential Causes
Heated water caused condensation and increased soap content
Written process calls for adding soap/water solution when there is a decrease in the fluid level of the tank
During cleaning, soap particles become free floating
Parts washer has not been at the appropriate level for the soap to dissolve properly
No filtering system exists between
the tank and nozzles

5. Cause & Effect Diagram Heated water causing condensation
Written process to add soap
Free floating soap particles
Nozzles
clogged
Temperature
Level too low for soap to dissolve properly
No filtering system between tank & nozzles
These are the possible causes of the problem:
Heated water causes condensation, which increases soap content.
Written process calls for adding soap/water solution when there is a decrease in the fluid level of the tank.
During cleaning, soap particles become free floating.
Parts washer temperature has not been at the appropriate level for the soap dissolve properly.
No filtering system exists between the tank and nozzles.
The effect is that the nozzles become clogged and are not spraying as freely as they should.

6. Cause & Effect Analysis
To help mitigate the causes, these steps can be taken:
Changing the percentage of soap solution to ensure soap solution dissolves completely
Use a different brand of soap solution which does not need to be as hot to dissolve completely
Install an inline filter to the line running between the pump
motor and nozzles
Move the pump off of the bottom of the tank
Add a strainer to the suction line
Check the water heater capability for hot water

7. Force Field Analysis
Issue: Parts Washer Spray Heads are Constantly Clogging
Driving Forces:
1. Water in the tank evaporates
leaving too much of the soap
solution behind; accumulation
of the soap solution could be
clogging the heads.
2. The temperature of the water
in the tank has not been sufficient
enough to properly dissolve the
soap solution; accumulation of the
soap solution could be clogging the heads.
3. The parts washer does not have filtration equipment installed between the tank, motor, and/or the spray heads.
Restraining Forces
1.This is the only parts washer now
approved by the EPA.
2.The parts washer is beginning to
slow the overall process which could
slow product time to customers.
3.Adding additional parts to the
washer to resolve the issue could cost
several hundred dollars and/or void
the warranty.

8. Possible Actions to be taken
1. Place an inline filter between the motor and the spray heads where it is accessible for cleaning and maintenance. 
2. Place the pump on a brick inside the tank so it will not pull water/soap solution directly from the bottom of the tank and add a strainer to suction line; the tank bottom is where 95% of the particles will settle keeping the pump directly off the bottom of the tank and adding a strainer on the suction line will keep most particles out of the heads.
3. Make repairs to water heater to keep constant temperature for best possible mixture/dilution of the soap solution.
4. Keep the lid of the parts washer closed during operation to lessen the evaporation caused by heating the water. 
5. Look into different soap solution that will better mix with the water and not require such a high temperature to lessen the water lost to evaporation.  
Actions which will have a strong likelihood of success and will be monitored corrective actions are:
1. Adding an inline filter system to the washer will catch all sediment not settled into the bottom of the tank. The filter can be cleaned on regular intervals to ensure it remains clean and serviceable. There are filters available on the market that will take out particles down to about a micron; a micron being smaller than the tip of a needle. It takes 25,400 microns to one inch of space. (Filtrationsystems.com, 2003)
2. Raising the pump off the bottom of the tank and adding a strainer to the suction line will help the pump pull only the water/soap mixture and not the particles that would have settled out onto the bottom of the tank. If the pump does not pick up the particles, they will not become lodged in the nozzles.
3. Verifying/updating the size/capability of the water heater will keep the water at a constant temp which will allow proper mixing of the soap solution and not let the water get so hot it evaporates.

9. Follow Up Actions
Monitor the number of days/hours between the last time the nozzles clogged before raising the pump and installing a strainer on the suction line and compare it to the next time it happens. If the times are far apart, then the fix is working and delays will be cut down if not totally eliminated.
Monitoring will also be necessary with the addition of the inline filter. The filter will need to be checked in accordance with manufacturers specifications in regards to the amount of water/soap concentrate being passed though it daily. When the filter is serviced, the contents can be monitored to see exactly what, and how much, is being filtered out of the washer.
Lastly, the water heater can be verified for accuracy by keeping an eye on a thermostat. Workers using the washer can check the temperature before each use and record it in a log book. The log book can be reviewed by maintenance personnel each shift. If there is a variance in the temperature, the maintenance personnel can make adjustments to the heater to correct the problem.
All corrective measures will be watched each shift for a 30-day period; if all is going according to plan, the next review will take place at the 60-day mark. After 60-days, if the nozzles are no longer clogging a normal maintenance schedule will begin in accordance with manufacturers specifications. If after 60-days there are still issues with the nozzles clogging, a new soap solution will be researched and a new plan for repair implemented.

10. Summary
The purpose of this study is to address the issues WP Inc. is facing by clogged spray nozzles in their parts washer. This issue has slowed production in the company and corrections need to be done to reduce downtime in the parts washer, thereby increasing production.
3 possible corrective actions have been taken and a plan of further action has been set for follow up:
Placing the pump at a higher level and install strainer
Installation of inline filter
Monitoring/repairing the water heater as needed
Results from lifting the pump and install the strainer will be tested as the first step. If insufficient improvement is shown, the filter will be installed and monitored at the beginning and ending of each wash process. Monitoring of the water heater will take place after the washer has been turned on with water and soap added, and before the parts are placed in the washer.
A time-line of 30 to 60 days has been set for this process.

11. References
Summers, D., Quality. (5th ed.) Upper Saddle River, NJ:
Pearson Education, Inc.
Filtrationsystems.com, Ultrafit Welded High Performance Liquid Filter Bags. Retrieved from