Document Revision No.: 2 Revised: 04/12/09 RIT KGCOE MSD Program
P09713 Bread and Roll Scaling Area
Test Plans & Test Results
By: Erik Webster and Kate Gleason
Table of contents
1. KanBan Test Plan 2
1.1. Introduction 2
1.2. Short-term Storage Kanban System 2
1.3. Test Strategy 2
1.4. Definitions; Important Terminology; Key Words 3
2. Table Top Simulation 4
2.1. Methodology and Procedure 4
2.2. Assumptions 5
2.3. Discussion of the Test Results 5
2.4. Conclusions 8
3. Kanban Control Plan 8
P09713 Bread and Roll Scaling Area
Test Plans & Test Results
1. KanBan Test Plan
1.1. Introduction
A kanban system will be implemented in the short-term storage area for the scaling operation as a visual aid for operators and fork truck drivers who will be replenishing the dry ingredients on a daily basis. It will be necessary to test this kanban system prior to and following implementation to ensure the daily time involvement for the fork truck resources are in line with the customer’s requirements.
1.2. Short-term Storage Kanban System
Currently, all dry ingredients for the scaling area are replenished based on the needs of that day as indicated on the batch cards. The batch cards describe the ingredients and quantity of each product that will be scaled that day. Once the individual Wegmans stores have placed their daily orders and the batch cards are received, a fork truck driver and the scaling operator examine the ingredients available in the scaling area and determine which ingredients must be replenished. The fork truck driver must then retrieve the pallets containing these ingredients and search for or make an open location in the scaling area to store them.
The kanban system is a visual aid that will allow the fork truck drivers responsible for replenishing dry ingredients in the short-term storage area to determine at a glance which ingredients must be replenished. Because this system will be based on the average daily use of each ingredient, it will be possible for the fork truck driver to replenish the area prior to the arrival of the scaling operator and the batch cards. The use of this strategy is expected to reduce the time involvement of the fork truck driver and the scaling operator because it will eliminate the need to determine which ingredients will need to be replenished based on the batch cards and the time spent searching for an open location for the incoming pallets of dry ingredients.
1.3. Test Strategy
1.3.1. Customer Needs and Project Specifications
An important customer need identified during the project definition phase was the process improvements would decrease the shift time for the scaling operator and decrease the time involvement for fork truck drivers in replenishing the short-term storage area. As seen in the table below, these customer needs were translated into project specifications that can be used to evaluate the effectiveness of the proposed kanban system.
Specification (description) / Unit of Measure / Marginal Value / Ideal ValueProcess Improvement Specifications
Shift time for scaling operator / hours / <10 / <8
Short-term storage replenishment time / hrs. / <2 / <1
Material remaining at time of short-term restock / days of volume / <1 / 0
Based on this table, the kanban system must contribute to the time savings in the scaling operator’s shift time. Also, the fork truck driver must spend no more than two hours each day transporting dry ingredients to the short-term storage area and ingredients will only be replenished when less than one day’s worth volume is available.
1.3.2. Phases of Testing
There will be two phases of testing for the kanban system. The first phase will be a table-top simulation that will be performed prior to implementation. The purpose of this simulation will be to estimate the time involvement for the fork truck driver each day using actual production data. The simulation will identify any issues or concerns that should be addressed prior to implementation.
The second phase of testing will be following implementation during the control phase of the project. The purpose of this second phase of testing will be to analyze and compare the actual time involvement of the fork truck driver each day with the estimate from the simulation. If the actual time involvement and the simulated time involvement are approximately the same, this will be an indication that the kanban system is performing as expected and meeting the project specifications.
1.4. Definitions; Important Terminology; Key Words
1.4.1. Short-Term Storage Area: The area from which operators retrieve dry ingredients for scaling products each day. This area holds at least one day’s worth of each ingredient by volume.
1.4.2. Table Top Simulation: A manual simulation performed on a table or a white board.
1.4.3. Scaling Operator: The operator responsible for measuring dry ingredients for the bread and roll products in the Wegmans Baker Facility.
1.4.4. Kanban System: A lean technique that uses visual aids to indicate when a specific action must to occur.
1.4.5. Expedite: The fork truck driver must replenish a dry ingredient during the shift because the scaling operation used more of that ingredient than expected.
2. Table Top Simulation
A table top simulation will be performed to analyze the kanban system prior to implementation in the Wegmans Bakery Facility. The purpose of this simulation is to verify the daily work responsibilities and time required for the fork truck resources to replenish the short-term storage area. If the kanban system meets the project specifications, the fork truck driver will spend less than two hours each day transporting dry ingredients to the short-term storage area.
2.1. Methodology and Procedure
To perform the table top simulation, data was collected for 22 days of actual production. This data included the bread and roll products that were mixed and the amount of each ingredient in pounds (lbs.) for each product. From this it was possible to determine the pounds (lbs.) of each dry ingredient in the short-term storage area that was used for each day of production.
The simulation was set up on a dry erase white board by drawing the proposed short-term storage layout and labeling each of the storage locations. Post-it notes were used to represent each pallet of dry ingredients and were placed in their respective locations. The kanban level was written next to each pallet. This level represents the minimum amount of each ingredient that must remain in the storage area before replenishment is required. Once the amount drops below this level, it is necessary to bring in a new pallet of that ingredient. The data collected prior to the simulation was then used to simulate what would have occurred each day if the kanban system were already in use.
The simulation started at time zero when each of the pallets in the short-term storage area was full. After each day of simulated production, the amount of each ingredient remaining in the storage area was indicated on the respective post-it note. If the amount of any particular ingredient fell below the kanban level, a new pallet of that ingredient was added to the area prior to the start of the next day’s production. Every time a post-it note was moved, it represented a task performed by the fork truck driver. Data was collected for the number of ingredients replenished prior to each shift, the number of ingredients that had to be expedited each day, and the number of times the fork truck driver returned to the storage area to move pallets to a lower shelf so that the scaling operators could reach them safely.
2.2. Assumptions
2.2.1. Fork truck drivers will only replace a pallet if there are 5 or less bags on the pallet. The remaining bags will be stacked on the incoming pallet. Otherwise, the pallet will be placed on the third shelf of the pallet rack, and the fork truck driver will return to move the new pallet down to the correct location when the previous pallet is empty.
2.2.2. It will be possible to expedite pallets because there is existing radio communication between the scaling operator and the fork truck driver.
2.2.3. At time zero each pallet in the short-term storage area will be full.
2.2.4. The time required for the fork truck driver to transport each pallet to the short-term storage area will be approximately 10 minutes, and the time required for the fork truck driver to move a pallet from the third shelf down to the primary pallet location will be approximately 5 minutes.
2.3. Discussion of the Test Results
The table below displays the results of the kanban simulation. For each day of production data was collected to determine the number of pallets that were transported prior to the start of the scaling operation, how many of these pallets had to be placed on the third shelf until the pallet in the primary location was empty, the number of pallets expedited during the scaling operation, and the number of times the fork truck driver had to move a pallet from the third or second shelf down to the primary storage location. For ergonomic reasons, the number of bags pulled by operators from second shelf pallet locations was recorded.
Day / Preshift Moves / 3rd Shelf / Expedited Pallets / Pallet Shuffles / Shelf 2 Pulls1 / 0 / 0 / 2 / 2 / 51
2 / 6 / 3 / 0 / 3 / 34
3 / 4 / 2 / 4 / 2 / 36
4 / 6 / 3 / 4 / 3 / 49
5 / 6 / 0 / 2 / 3 / 36
6 / 10 / 3 / 3 / 5 / 29
7 / 7 / 1 / 1 / 1 / 51
8 / 4 / 3 / 0 / 5 / 30
9 / 8 / 4 / 1 / 4 / 48
10 / 10 / 2 / 6 / 1 / 48
11 / 9 / 3 / 2 / 3 / 38
12 / 8 / 3 / 1 / 6 / 44
13 / 9 / 3 / 0 / 2 / 43
14 / 6 / 5 / 1 / 6 / 27
15 / 8 / 4 / 1 / 5 / 29
16 / 6 / 1 / 5 / 4 / 46
17 / 9 / 1 / 2 / 3 / 34
18 / 7 / 3 / 2 / 4 / 37
19 / 6 / 4 / 0 / 5 / 34
20 / 11 / 6 / 0 / 7 / 20
21 / 6 / 3 / 1 / 5 / 43
22 / 11 / 3 / 2 / 5 / 42
Total / 157 / 60 / 38 / 82 / 798
Average / 7.48 / 2.86 / 1.81 / 3.90 / 38.00
Stdev / 2.06 / 1.39 / 1.72 / 1.64 / 8.32
Max / 11 / 6 / 6 / 7 / 51
Min / 4 / 0 / 0 / 1 / 20
From this data it was possible to determine the average daily occurrence for each of the items described in the table above. The maximum and minimum number of daily occurrences for each of the items over the 22 days of production was determined as well. From this information, it was possible to estimate the amount of time spent each day by the fork truck driver replenishing materials in the short-term storage area based on the assumptions made previously. The table below contains the calculations for these estimates.
Fork Truck Task / Task Time (min) / Daily Frequency / Total Time (min)Preshift Pallet Move / 10 / 8 / 80
Expedite Pallet / 10 / 3 / 30
Shuffle Pallet / 5 / 4 / 20
Total / 130
Based on this table, the project specification for the amount of time devoted by the fork truck driver each day to replenishing the short-term storage area has not been met. The specification stated that the total time must be less than 2 hours each day. However, during the simulation, several trends or patterns were discovered. The majority of the tasks performed by the fork truck driver concentrated on only a small percentage of the ingredients in the short-term storage area. As seen in the table below, only 10 out of the 44 ingredients were expedited over the 22 day period.
Ingredient / Gran Sugar / Vital Wheat Gluten / Specialty Stoneground / Stoneground / Hearty Bread Base / Canadian Oat Base / Watson Oat Bran Base / Watson Lite White Base / Watson Honey Bran Base / Ultra GrainPallets Used / 6 / 17 / 28 / 46 / 9 / 4 / 2 / 4 / 7 / 20
Pallets Expedited / 1 / 1 / 11 / 5 / 4 / 1 / 1 / 2 / 2 / 5
% of Total Expedited / 3.03% / 3.03% / 35.48% / 15.15% / 12.12% / 3.03% / 3.03% / 6.06% / 6.06% / 15.15%
The three ingredients with the highest volume, stoneground wheat, specialty stoneground, and ultra grain, accounted for approximately 66% of all the expediting that occurred during the period of simulation. Upon completion of the simulation, the layout of the short-term storage area was revisited, and additional storage locations were added for specialty stoneground and ultra grain. However, it was not possible to create additional storage locations for stoneground wheat. This change in the layout is expected to eliminate the need to expedite specialty stoneground and ultra grain on a regular basis. As a result, the number of pallets expedited pallets will be 1 to 2 each day. This will reduce the replenishment time for the fork truck driver to within the acceptable level of 2 hours.
Another issue that was discovered during the simulation was that the kanban levels were often too low, causing expediting to occur more frequently than necessary. The calculations used to determine the kanban levels were reexamined and a critical error was found. The kanban levels were created by calculating the average daily use of each dry ingredient over time. However, the fact that each ingredient is used some does and not on others was not considered. So the kanban levels were recalculated for each ingredient only the days on which that ingredient was used. This increased the kanban level for several ingredients that were expedited in the chart above. This is expected to decrease the number of pallets must be expedited and reduce the replenishment time for the fork truck driver in the short-term storage area.