Simulating Produce Coolers: Challenges and OpportunitiesKhaled MabroukOperational Engineering Leader - SPS

Presentation Outline

• Ag/Produce Business in California• Operational Engineering & Farming• Produce Cooler Processes• Produce Cooler Simulation

America’s Salad Bowl

• Top Crop States:CA $44.7B, IA 31.9, NE 24.4, TX 22.7, MN 20.5

• CA generates 15% of USA crops,and 50+% of USA grown fruits, nuts, and vegs

• Watsonville & Salinas Valley generates $4.7B

Along Central Coast (South of Bay Area)

Produce Business

• Some companies only fill one or two of these roles, and some are totally vertically integrated.

Seeds & Seedlings Providers

Growers

Harvesters

Shippers

High Level Look at Growing Process

Prep Land (2 days)

List Field (1 Day)

Prep Beds (1 Day)

Plant Field (4 Acres/Day)

Transplant Drench (7 days)

Light Irrigation (7 days in

Summer, 14 days in Spring/

Fall)

Side Dress (1Day)

Irrigation & Check for Pest/

Disease (intermittently until harvest)

Harvest Field

Detailed Look at Growing Process

Planting,Growing,

HarvestingProcess

SchedulingProcess

Decide on desired volume for next season. With a focus on Peak

Demand periods.

Meet with sales people to verify

demand projections

Meet with production people

to discuss allocation of demand to land

Based on varieties, land base, crops: generate time to harvest maturity

numbers

Use time to harvest estimates to back

into planting schedule; including

second crop.

Adjust planting schedule based on soil type, weather, crop type, seed/transplant. etc.

Is projected planting time after spring?

Expect to adhere to planting schedule

most of time

Expect to modify actual planting time

due to weather issues.

Prep land, includes:adding compost,

gypsum, lime, sulphur (as

appropriate)

List Field Plant Field

Generate tentative harvesting schedule

Growers schedule equipment, people,

and irrigation; based on Wet date

of planted field

Harvesters schedule equipment and

people

Harvesting & Sales people meet to discuss volume

projection

Harvest Manager & Grower arrange to give field shot of

water; if necessary.

Yes

No

Execute irrigation, other growing

practices as needed

Finalize schedule one week before

harvest

Adjust schedule daily based on

communications between grower &

harvesting mangers; until day of harvest

Harvest FieldWill this field be

harvested again?

No

Yes

Prep Field for planting, includes:

pre-irrigation, cultivation, bed shape, fertilizer,

insecticide, herbicide (as appropriate)

OE & Produce Growers Shippers

• Optimization models for field planting selection

• Best Practice Standard Work for field work• Predictive Maintenance for Field Equipment• Simulation of Produce Coolers

Produce Cooler Example

Produce Cooler ProcessesQueue Truck for

ReceivingI/ B

Truck

QC checks product

Forklifts unload pallets

Receiving updates

inventory

Receiving verifies

product, and print stickers

Forklifts place pallets under shade bays

Forklifts Move pallets to

Vacuum Tube 01 or 02

Forklifts Move pallets to Ice

Injection 01 or 02

Forklifts Move pallets to Wet

Box doors

Forklifts Move pallets to Dry

Box doors

Loaders Place Pallet in racks

Forklifts Move pallets to Hydra-Vac

Loaders move pallet to Forced

Air Cooling Tunnel

Pallets wait for cooling process

to complete

Forklifts Move pallets to Dry

Box doors

Accumulate appropriate number of pallets for

cooling process

Execute Cooling Process

Accumulate appropriate number of pallets for

cooling process

Execute Cooling Process

Accumulate appropriate number of pallets for

cooling process

Dry or Wet Cooling?

Wet Cooling Type

Dry Cooling Type

Dry

Wet

AFC

Vac Tube

IceInjctr

HydraVac

Arrival Rates

Cooling Approach By Product

Produce Cooler Challenges

• Produce degrades quickly• Must be in cooler within 2.5 hours of

harvesting, takes 30-60 minutes for product to arrive

• Each product has it’s own cooling requirements; process and time in process

• Different forklifts for inside vs. outside cooler; concern about emission affect on product

Produce Cooler – Simulation Challenges

• Must keep track of every pallet• Arrival pattern varies by time of day• Should wait for sufficient number of pallets of

a product type before starting cooling process• Use shade bay for staging• 12 pallet forklift

Produce Cooler - Sample Model

• There are many excellent simulation software products.

• The use of a specific product on this project is not an endorsement for any one specific simulation software.

• Let’s RUN THE MODEL

Lessons Learned

• Tube capacity should be a multiple of 12• Extra receiving personnel needed during busy

period to reduce in-bound trucks queuing• Room available in Shade Bay Area to convert

to other use• Both Dry & Wet Boxes are sized appropriately• Single move for AFC products has significant

impact on Average Time to Complete Cooling Process