FINAL PROJECT

Ind E 337/537 Final Report
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Project Definition
PROJECT: Potbelly Sandwich Shop Process Improvement
BY: Sean Nguyen and Michael Tran
DATE: December 10th, 2014
Objectives: Improve the efficiency of the production process, and reduce production errors at
Potbelly Sandwiches through the implementation of lean manufacturing
practices and tools.
Benefits: Through the implementation of lean practices and tools, we feel that this will
provide Potbelly with long-term benefits that will improve the company as a
whole, including:
● Reduction in lead time
● Improved product quality, and higher customer satisfaction
● Reduction in the number of product errors
Background: The reason this project needs to be undertaken is due to the fact that Potbelly
Sandwiches does not have their sandwich production process fully optimized. If
practices such as 5S and identifying waste reduction are established within the
business, they can serve as a structure for all employees to follow which will
bolster the company altogether.
As it stands right now, there are several instances of idle time in the production
process that we feel can be reduced through the implementation of the tools that
will be mentioned below.
Process: This project will be accomplished by performing the following six tasks:
1. Value Stream Mapping of products and services critical to Potbelly
Sandwiches
Through the creation of a value stream map we will be able to identify the current
state of the sandwich production process, analyze activities where there is waste
or non-value added, and from that, create a future desired state in which
production is further optimized.
2. Specific opportunities to reduce seven types of muda as identified
by the TPS

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By identifying and eliminating waste, the sandwich production process will
improve in efficiency and quality. Creating a waste free environment is important
to ensure the system does not waste time and resources in processes that do not
add value.
3. Time and Motion Study of important assembly activities
Through the use of a Time and Motion study it will enable us to see what the
employee is doing through the entire process. From this we can find out where
the employee is performing effective and ineffective tasks, and find ways to
reduce the amount of ineffective tasks.
4. Introduction of 5S and visual controls
The application of 5S is critical in creating a high quality and sustainable work
environment. Through the use of 5S, we hope that Potbelly Sandwiches will have
work environment that is not only clean, but efficient as well.
5. Conducting a Kaizen Event at Potbelly
From our Kaizen event, we aim to reduce the lead time on sandwiches and
improve efficiency, and we hope that this event will carry along into the future as
Potbelly continually looks for ways to optimize the production process.
6. Create an A3, including an Ishikawa Diagram for the current state
of a problem
Through the use of an Ishikawa diagram we hope to get to the root of production
error and solve it, as it is imperative sandwiches are made correctly. Correctly
made orders will not only save material being wasted, but also improve customer
satisfaction, and ensure that a product is made to the highest of Potbelly
standards.
Scope: We hope that the processes undertaken in this project, particularly the sections on
5S and reduction of waste, will become commonplace in the work area, and be
taken upon by every employee at Potbelly Sandwiches. This project could also be
applied to other similarly structured businesses such as other sandwich shops, or
any “fast-casual” restaurants in which customers choose the ingredients that go
on their product.
Owners: This project was created by Sean Nguyen and Michael Tran.
Participants: Potbelly Sandwich Shop, Travis Neu (Store Manager), Lindsey Johnson (General
Manager), Production Line Employees, Microsoft Word, Microsoft Powerpoint,
and Customers of Potbelly Sandwiches.

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Ind E 337/537 Final
Report
Potbelly Sandwich Shop Process
Improvement
December 10th, 2014
By: Sean Nguyen and Michael Tran
Table of Contents
Executive Summary…………………………………………………………………………...…..………...5

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Discussion…………………………………………...…………………………………..…..……...…..…..6-14
1. Value Stream Mapping…………………...………………………….….…….........................6-7
2. Specific Opportunities to Reduce Seven Types of Muda………….…….…………......7-8
3. Time and Motion Studies of Sandwich Production…………………….……………………9
4. Introduction of 5S and Visual Controls………………………………………………………9-12
5. Discussion of Kaizen Implemented at Potbelly………………………………………………13
6. A3 Diagram of the Current State……………………………………………………….…………13
Conclusion and Recommendations…………....………………………………….………………14
Appendices………………………..…………………………………………………………………..……..15-17
1. Appendix A……………………………………………………………………………………………15-16
2. Appendix B………………………………………………………………………………………………...17
References………………………………………………………………………………………………………..18
Executive Summary
This report is an analysis of Potbelly Sandwiches’ production process. We conducted this study
through the use of lean manufacturing tools and principles including: value stream mapping of
the products critical to Potbelly, analyzing and identifying seven types of waste on the
production floor, performing time and motion studies of sandwich production, introducing 5S
and visual controls, introducing a Kaizen, and performing problem solving analysis through the
use of an A3 diagram.
During our time with Potbelly Sandwiches, we observed that the sandwich production process
was not yet fully optimized as there were several occurrences of wasted or idle time, and also

5
occurrences of product defect. These inefficiencies in the production process resulted in
increased lead time for the customer and, on occasion, waste of material and resources. Through
the recommendations outlined in this report, the sandwich production system can become more
efficient while also ensuring top-quality product and customer satisfaction by adopting
methodologies from lean manufacturing.
Discussion
The following sections will discuss the six processes mentioned in the project definition that we
used to accomplish this project.
Value Stream Mapping
The Value Stream Map (VSM) shown below in Figure 1 depicts and visualizes the flow of critical
information for the sandwich production process at Potbelly Sandwiches. At an average daily
demand of 100 sandwiches, and a standard day of 12 total working hours, the maximum
required takt time for the system is calculated to be at 500 seconds [3]. Upon observing the
system, the takt time was easily filled as the total lead time from when the customer begins
placing their order to when they receive their product was, on average, only 230 seconds (3.833
min).

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Figure 1. Value Stream Map of Sandwich Production System
With usually only one or two employee working on the floor, a single-piece flow system was
implemented. The major area for concern in this system is the stage between the toaster
workstation and the topping workstation. The toaster is able to toast prepared sandwiches at a
fixed time of 60 seconds, while the two stations after the toaster stage require a total of 70
seconds. Because preparing sandwiches before the toaster stage takes around 24 seconds, a
bottleneck occurs at the buffer between the toaster and topping workstations. Sandwiches here
must wait for the employee working the topping and cash register stations to finish before
moving forward, leading to 70 seconds of waiting. Though this does not affect the quality of the
product (the end of the toaster keeps the sandwich at a safe, constant heat), it greatly increases
the lead time for the customer. In order to increase efficiency and reduce the lead time, the
process of applying toppings must be streamlined. By optimizing this workstation, sandwiches
will not have to wait at the previous buffer (represented by the star on the VSM), thus making
the lead time closer to the total cycle time of 160 seconds (2.67 min). Our recommendation for
the change in the process will be outlined later in this report by the use of Time and Motion
Study.
Specific Opportunities to Reduce Seven Types of Muda Identified
by the TPS

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During our time at Potbelly, there were several different types of waste that occurred while
making a sandwich. These occurrences will be discussed and examined below, in seven different
categories [2].
● Waiting: This type of waste was the most apparent at Potbelly, and had the highest
degree of repercussions associated with it. Every sandwich made at Potbelly would go
through the toaster for exactly one minute. During this minute the employee would wait
for the sandwich to finish toasting, performing no additional task if there was not
another customer in line. After the sandwich came out of the toaster, the employee
would then have to wait for a customer to decide what ingredients they wanted on their
sandwich before moving onto the next step of the process. If the employee were to take
down the ingredients the customer wanted while the sandwich was in the toaster, it
would not only reduce wasted time of the employee standing around, but also reduce the
time waiting for a customer to choose their ingredients to essentially no time at all.
While a wasted minute may not appear as much, every second matters at Potbelly. At
Potbelly, their promise to customers is that an entire order will take eight minutes at
most to complete. Reducing the amount of waiting time will allow Potbelly to remain
true to their word. The exact numbers of waiting time, and further methods to reduce it,
will be discussed in the Time and Motion study section of this report.
● Correction: Every so often an employee would make a mistake on the sandwich a
customer ordered. This would result in the employee having to completely discard of the
defective sandwich and start over on the order once again. This, in turn, results in wasted
material and extra work having to be done on the employee’s part. Examining this
problem in its entirety, and finding a way to solve it, will be discussed in greater detail
later on in the report through the use of an A3 diagram.
● Confusion: When an order is placed, the employee puts the ingredients onto the
sandwich through memory and prior training. This is where confusion can occur as there
is no ingredients sheet, or written down information for the employee to double check
that they are in fact correctly putting the sandwich together. This confusion of not
completely understanding the menu leads to defects, and unsatisfactory sandwiches.
This type of waste can be removed by aiding the employee with visual tools, notably
labeling, and will be further discussed in the 5S portion of this report.
● Inventory: At Potbelly they aim to deliver their customers fresh sandwiches, with fresh
ingredients. With this company policy implemented, it means that Potbelly is ordering
breads, vegetables, and meats everyday based on a daily forecast. What happens with
leftover ingredients is that they are discarded at the end of the day. This disposal of
leftover ingredients has the same effects as producing a defective sandwich, resulting in
wasted material and resources. This type of waste can be reduced by conducting studies
on demand, and minimizing the amount of excess material ordered each day.
● Over-Processing: This type of waste was a rare occurrence, however, from time to
time an employee would put too much of an ingredient on a sandwich. This would result

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in the customer asking the employee to remove the excess ingredient, which in turn
resulted in wasted resources. This type of waste can be reduced by having employees
work under a standardized policy.
● Under Utilisation of People: This type of waste was rather difficult to observe on the
production floor. However, the under utilisation of the employees comes with the
constant cycling of different jobs. On the floor, an employee will cycle between making
sandwiches, milkshakes, salads, and even being the cashier. If an employee is partially
inept at any task, it will show in the final product. Instead of the constant cycling,
employees should be assigned to the tasks they are most talented in which will result in
happier employees and improved quality of product.
● Motion: Waste of motion occurred when an employee would go to grab gloves. These
gloves were frequently needed, and were inconveniently placed on the counter opposite
the production area. This resulted in the employee making unnecessary turns back and
forth. This waste of motion, and how it can be reduced, is further examined in the Kaizen
and 5S sections of this report.
Time and Motion Study
A Time and Motion Study (TMS) was conducted on the sandwich production system to analyze
the system from the viewpoint of the employee, allowing us to see where improvements could be
made in the process. The current state process, attached in Appendix A (Figure A.1), shows that
the right-hand does the vast majority of the effective work. We believe that implementing more
left hand use will speed up the process while maintaining product quality. It can also be
observed that the employee spends a lot of idle time with both hands during the entire
procedure. While the sandwich is going through the toaster, the employee needs to remove and
dispose of their gloves and retrieve and put on a new pair. Afterwards, however, the employee
spends the rest of the toasting time idle. During the application of toppings, even more idle time
is spent due to time spent talking to the customer to figure out which toppings they desire. After
applying their desired mayonnaise or sauce, the customer then must decide what vegetables
they want. After applying vegetables, the customer then finally must decide what seasonings
they want. These are the critical areas where we believe the system could improve the most.
The proposed, future-state TMS is attached in Appendix A (Figure A.2). The first change is in
the preparation stage, where we propose the use of both hands while applying the meat and
cheese to the bread. By using both hands to do this standard task, the system can possibly shave
off a few seconds. The major proposed change, however, takes place during the time the
sandwich is in the toaster. In the current state TMS, it can be seen that the employee spends 46
seconds idle while the sandwich is toasted. Our proposal is that the employee utilizes this time
to record the topping information from the customer. By doing this, the employee is not idle

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during toasting, as well as being able to remove the idle time wasted when the customer is
picking their toppings in the following workstation. Writing down this information not only
removes all of this idle time, but also reduces confusion and the chance of error, which will be
discussed in the following section about the implementation of 5S and Visual Controls.
Introduction of 5S and Visual Controls
The introduction of 5S and visual controls are necessary at Potbelly Sandwiches in order to
create standardized and sustained work [2].
● Sort: The production area of Potbelly Sandwiches was relatively clean, as will be later
discussed in the “Shine” section. However, there were still items lying around that were
not needed in the work area. As seen in what is circled in Figure 2 below, there are
several stacks of cups sitting around that cause clutter. Having that many extra cups
sitting around is unnecessary, as they can simply load excess cups into the storage room.
Figure 2: Location of Cup Stock
● Set: When a customer orders a sandwich, the employee, going off of memory and
training, would grab the necessary ingredients required for that particular sandwich.
This would result in error from time to time as the employee would accidentally grab the
wrong type of bread, or add the wrong type of cheeses or meats. The percentage of this
error occurring would increase during peak hours at lunch or dinner, as the employee
would try to hurry through orders in order to get past the rush. By having a visual
labeling system in which the various types of breads, cheeses, and meats are easily
differentiated, as well as marking topping choices on the wrap paper, we feel that this
will not only improve the efficiency of the production process, but also significantly
reduce the number of errors made.
To add to this, when an employee makes a sandwich at Potbelly, they frequently have to
switch out gloves during the creation process. These gloves, however, are located on the

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opposite side of the processing area, as seen in Figure 3 below. The rearrangement of this
item will be further discussed as a Kaizen event later in this paper.
Figure 3: Employee Grabbing Gloves
● Shine: The employees at Potbelly sandwiches already seemed to perform at a high level
on the shine aspect of 5S. During our time at Potbelly, we would frequently see workers
cleaning up the production area on a constant basis. This included everyone from the
management staff to the cashiers; everyone was involved in the cleaning process. As seen
in Figure 4 below, the production area is very neat and tidy, and free of any debris.

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Figure 4: Clean Work Area
● Standardize: At Potbelly, it was observed that employees would frequently switch
between doing different jobs. For example, an employee would be seen making a
sandwich, doing paperwork in the backroom, and become the cashier all in a span of 30
minutes. This was understandable as the Potbelly staff was relatively small in number;
however, this constant swapping of jobs resulted in unstandardized work. We observed
that different employees had different methods of how they performed the job. This was
particularly noticeable in how they identified the sandwiches. When a sandwich was
done being made it would be wrapped, and then put into a bag essentially making it
unidentifiable to whoever was the cashier at the time. Some employees would use a pen
and write down the order on the bag; however, more times than not, the sandwich would
not be marked. This raised the constant question of, “what did you order today?” which
would not only bring concern of a customer lying about their order, but also prolong the
time it took for a customer to enjoy their sandwich. By having a standardized work
routine, it will improve the efficiency of the line and make the responsibilities of the
employees better known.
● Sustain: Without sustaining these practices, all the aforementioned steps are rendered
useless. Every employee at Potbelly Sandwiches must hold themselves accountable for
not only the cleaning of the store, but also for producing a product that is of high quality.
Kaizen Event

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A Kaizen event we recommend for the company to conduct would be the relocation of the gloves
needed during the sandwich making process. After discussing with the manager and employees,
using new gloves for both the preparation stage and toppings stage of the process is necessary in
order to ensure there is no cross-contamination between ingredients. The employees are
required to frequently remove and dispose their first pair of gloves and then retrieve and put on
a second pair. The current location (previously mentioned in Figure 3 above) of gloves is not
optimal and requires the employees to move to the other side of the work area in order to
retrieve a new pair, which results in a waste of both time and motion.
As seen in our Time and Motion Study, the application and removal of the two pairs of gloves is
standard in the sandwich making process. Because it is a necessary step in the process, the
location of the gloves should be close to the other parts needed to create the product. By having
the gloves on the same side of the work area with the ingredients, employees will be able to more
quickly apply new gloves, use the time saved more effectively, and thus be able to create
sandwiches more efficiently. To further expand on this recommendation, having a stock of
gloves at the very beginning of the line as well as directly after the toaster could simplify and
standardize the process. Having the gloves be placed alongside the assembly in the process
ensures that employees will “flow” down the line and be able to easily select the items right when
they are called for.
Use of an A3 including an Ishikawa Diagram
The primary problem that occurred during the production process was an error being made in
the sandwich. These errors that occurred were mainly human based errors; however, from time
to time the machine would make errors as well.
When a customer placed an order the employee would not write anything down and instead take
the entire order down mentally. This would result in error from time to time, occurring at
various places along the production line, as there was no mistake proofing made along the way.
By taking down the order mentally, the employee would become overloaded with information
particularly during a rush hour or when having to deal with multiple orders. This would result in
the employee accidentally grabbing the wrong type of bread, or cheese, or even
misunderstanding the customer. In addition, there was generally only one employee on the
production floor, which meant that there was a chance of an employee unknowingly giving a
customer a defective sandwich, without anyone there to double check their work.
In addition to human error, there was machine error involved in the process as well. With
different sandwiches, there would be occurrences of a sandwich being either too toasted to the
point of being burnt, or not being toasted enough to customer satisfaction. This would occur
primarily due to the fact that the toaster setting was the same for all sandwiches. When we
talked to the manager, he mentioned how all sandwiches are toasted for one minute regardless
of what type they are.
Consequently, these errors would result in the employee having to start over on the order and
discard of the defective sandwich, as they did not want to use the now defective ingredients in

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another sandwich. This disposal of material, and restarting of the production process, directly
contributed to increased lead time and waste of material.
To aid these errors, we have made suggestions in the A3 diagram that is attached in the
Appendix B below as Figure B.1. We hope that the use of this A3 will help solve the problem of
defective sandwiches.
Conclusion and Recommendations
All in all, Potbelly creates high quality sandwiches that are manufactured in a clean work
environment. However, there is room for improvement in the production process in terms of
efficiency and reducing error. By implementing the lean manufacturing tools and practices that
have been discussed and recommended in this report, Potbelly will be able to deliver sandwiches
to customers at a faster pace, reduce variability between products, and, in turn, create a
sustainable work environment in which all employees are able to perform to the best of their
capabilities. We hope that Potbelly Sandwiches will appreciate the discussion raised in this
report, and take these recommendations into consideration. We fully thank them for their time,
patience, and cooperation.
Appendix A

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Figure A.1: Time and Motion Study (Current State)

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Figure A.2: Time and Motion Study (Proposed Future State)

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Appendix B
Figure B.1: A3 Diagram [1]
References
[1**] J. Shook, “Detailed A3 Template (from Managing to Learn).” Internet:
http://www.lean.org/a3dojo/ContentList.cfm?MTLCategoryId=14, July 19, 2010 [Nov. 28,
2014].
[2] Nicholas, John. Lean Production for Competitive Advantage. New York: Taylor and
Francis Group, 2011. 1-307. Print.
[3] Travis Neu, Shop Manager: Personal Interview (2014);
Lindsey Johnson, General Manager: Personal Interview (2014).

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**We used this sources A3 template. However, the writing on the template and the Ishikawa
diagram is 100% our own work.

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