2. PROBLEM DEFINITION
Technology Exporters U.S.A has been hired by New World Energy’s (NWE) board to assist in
the planning and design of the proposed 1.0 Megawatt/Month PV panel production facility which
is basically the goal of the study. The purpose of the study is to report Heinrich Grünfuror,
NWE’s Chief Technical Officer by generating a process plan, based on the information provided,
for the PV panel production process.
Some of the questions that may be encountered during our study are how to generate a process
plan, how to produce a graphical representation of this production process, how much of a
capital investment will NWE have to make to develop a pilot production facility in Akureyri
Iceland, what will be NWE’s total capital investment for the final production facility, what will
your staffing requirements be for the pilot production facility, what shift patterns and staffing
levels should be used to run the Akureyri facility during each phase of our production expansion.
Once the pilot production facility is up and running, the NWE board will allocate a maximum of
$600,000 per month in new capital investment provided that each additional investment of
capital can be proven to result in a significant increase in PV panel production numbers. Based
in this funding profile, provide an estimated capitalization plan for incrementally bringing the
Akureyri facility up to full capacity. This may be considered as the problem we may face during
the project because we have to spend under $600,000 per month. Also we have to manage the
shift of our staffs and manage the proper staffing levels in proper time. Moreover, there will be
some problems while preparing source silicon material such doing purification by removing
contaminants and oxides from raw silicon. These are problems which we must know in order to
solve them.
3. PROJECT PLANNING
Event Time Date Resource
Understand and Define the Problem 2 hours 3/25/13 Handout
Project Planning 3 hours 3/26/13 Excel
System Definition 3 hours 3/27/13 Word
Conceptual Model Formulation 6 days 3/2813 -
4/3/13
Flow Chart, Igrafx
Preliminary Experimental Design 3 hours 4/4/13 Word
Input Data Preparation 5 days 4/5/13 –
4/9/13
Excel, Word
Model Translation (Do simulation on the
Model)
7 days 4/10/13 –
4/16/13
witness 2.0
Verification & Validation (Analysis the Model
with Different changing Tasks)
2 days 4/17/13 –
4/18/13
witness 2.0,Word
Final Experimental Design (Use the resource
Given by Technology Exporters U.S.A)
2 days 4/19/13 –
4/20/13
witness 2.0
Experimentation 8 days 4/21/13 –
4/28/13
witness 2.0, Excel,
Graph
Analysis and Interpretation (Answer Mr.
Grunfuror’s questions)
4 hours 4/29/13 Word, witness 2.0
Implementation and Documentation (Write and
concluded the results with a report)
2 days 4/30/13 –
5/1/13
Excel, witness 2.0
4. SYSTEM DEFINITION
1. Preparing Source Silicon Material
The raw mined silicon must be cleaned and purified before it can be used for silicon
wafer production. The raw silicon will be provided to the factory by the truck load. The
raw silicon will be stored to hoppers which deliver the crushed silicon ore to the factory’s
ore purification facility. The objective of the ore purification process is to remove mineral
contaminants and oxides from the raw silicon. This is done by first cleaning the silicon
ore using a chemical cleaning process and then placing the cleaned ore in industrial ovens
where it is heated until it is transformed into a molten state. As the ore melts, impurities
are released from the ore which tend to congregate at the top or bottom of the molten
material. This material is then manually inspected and sorted into three material grades:
A-grade silicon, B-grade silicon, and byproduct.
2. Producing a 420 kg Production Grade Ingot
This process will generate production grade ingots of polycrystalline silicon that can be
sliced into wafers that can be converted into photovoltaic cells. This process includes 420
kg production crucible preparation, production grade ingot processing.
3. Silicon Brick Production
This process will generate “bricks” of production grade polycrystalline silicon that can be
sawed into silicon wafers. This is achieved through a series of process steps: Ingot
Preparation, Ingot Dicing, Brick Trimming, Brick Inspection and Sizing.
4. The Wire Saw Area
This process will cut the bricks into stacks of wafers. A wire saw is used to perform this
process. When the block sets are removed from the saw, they are placed in a solvent tank
where hot solvents are used to loosen the glue that holds the wafers to the glass substrate.
The process includes block set production and wire saw operation.
5. Wafer Separation and Packing
5. In this part of the facility, wafer handlers are responsible for dismounting the wafers from
the sliced block mounts. These individual wafers are cleaned and inspected. These
wafers are scrapped. This is the end of the simulated process.
CONCEPTUAL MODEL FORMULATION
6.
7.
8. PRELIMINARY EXPERIMENTAL DESIGN
In preliminary experimental design, system performance measures would be the amount of
Wafers (parts) shipped by the factory by the end of each month. The factors to be varied would
be the number of shifts, labors and equipment used in the production facility. The level of these
factors to be investigated would also be putting into consideration.
INPUT DATA PREPARATION
EquipmentsInvolved Description(time,type,etc) WitnessElement
Raw Silicon dumpedbytruck Entities
Hoppers 1500kg Buffer
A-grade Silicon 38% Entities
B-grade Silicon 45% Entities
Byproduct 17% Entities
Ore cleaningbasket Quantity= 1 Buffer
QuieuingConveyer Basketconveyed Conveyer
ore cleaner 50 minutes activity
chemical process 10 minuteseach machine station
industrial dryers 90 minutes machine station
furnaces Quantity= 1 activity
PrimaryRinse 10 minutes activity
Base Rinse 10 minutes activity
Base Bath 10 minutes activity
DeionizedWaterRinse 10 minutes activity
AcidBath 10 minutes activity
600 kg crucible Quantity= 1 Entities
420 kg crucible Quantity= 1 Entities
release agent Quantity= 1 activites
storage 6 bakedcrucible buffer
9. Oven 4 crucible activity
inspection Quantity= 1 activity
release agent Quantity= 1 activity
material bin Quantity= 1 buffer
PaintBooth 600 kg Batch Machine
coolingcycle 10 hours buffer
purificationcrucible attribute activity
hydrauliccoolingstation Quantity= 1 machine station
crushingstation batch machine machine station
crucible preparation Single Machine activity
brickproductionarea setuptime 17 machine station
saw dicingpallet (12 hours)cutting,removal activity
brickinspector Quantity= 1 activity
wire saw loadand unload machine/activity
operator Quantity= 1 activity
solventtank productiontype machine
shipment packing activity
A-Bin 120 kg Buffer
B-Bin 121 kg Buffer
c-Bin 122 kg Buffer
11. MODEL TRANSLATION
I have broken down the model phase into two phases.
Phase 1: First of all the raw silicon ore is sent to the ore cleaner. The raw silicon will be stored to
hoppers which deliver the crushed silicon ore to the factory’s ore purification facility. Then it is
dried and sent to preparation machine where it produces A grade material, B grade material and
by product. For Purification crucible is sent to the crushing system and then a sorting system.
After that they are sent to A grade, B grade holding bin and recycled through factory or sent to
the production line, the waste product is then sent back to the mine.
12. Phase 2: For the production line, the good crucible is sent through the production line
where it is cut, glued and separated into blocks and then put in the solvent tanks. Then
“bricks” are produced through a series of process steps: Ingot Preparation, Ingot Dicing,
Brick Trimming, Brick Inspection and Sizing. The bricks then are cut into stacks of
wafers through wire saw. Lastly these wafers are separated and packed.
VERIFICATION AND VALIDATION
The model confirms that it operates the way as intended without any errors. The model runs all
the way to 12 months without any blockage. The model works well since all the system elements
such as entities, activities, resources and controls have no errors and are processed as the analysts
expected. Therefore I assume that it is a valid model.
17. When I ran my model to 564,480 minutes (an additional one year in minutes), I found the busiest machine
to be furnace in my model that has busy percentage of 74.91%. The labor, assembler has busy percentage
of 46.44%. Therefore I can assume that the bottleneck of my model or system is furnace. When I ran the
model to 564,480 minutes with 40320 minute warm up, I have a total of 3746 wafer stacks
shipped.
18. FINAL EXPERIMENTAL DESIGN
The base model produced will be used in my final experimental design. When I ran the model to
564,480 minutes with 40320 minute warm up period by having seven workers working 8hrs shift
5 days a week, I have a total of 3746 wafer stacks shipped in my base model. I modified my
model every month by adding the furnace, adding wire saw, giving shift to the operators and
more and finally came up with the Final model which is MONTH 12 model where I have a total
of 31322 wafer stacks. Below is my Model:
FINAL MODEL
19.
20.
21.
22. EXPERIMENTATION
Month 1
I added a furnace in the first month. When I ran this model to 564,480 minutes with 40320
minute warm up, I have a total of 7365 wafer stacks shipped.
Month 2
I added shift to cleaner, assembler and operator to night shift. When I ran this model to 564,480
minutes with 40320 minute warm up, I have a total of 8312 wafer stacks shipped.
Month 3
I added a wire saw in this month. When I ran this model to 564,480 minutes with 40320 minute
warm up, I have a total of 9454 wafer stacks shipped.
23. Month 4
I added one more furnace in this month. When I ran this model to 564,480 minutes with 40320
minute warm up, I have a total of 11279 wafer stacks shipped.
Month 5
I assigned assembler to work in waffle handling station. Then I assigned Assembler morning
shift and wafer handler night shift. In this case I have a total of 11867 wafer stacks.
Month 6
I added one more furnace in this month. In this case I have a total of 13886 wafer stacks.
24. Month 7
I added morning shift to Saw operator, Furnace operator and Cleaner and then added night shift
to Purifying operator, Inspector and Saw operator. In this case I have a total of 16231 wafer
stacks.
Month 8
I added two more paint booth and two more soaking station. In this case I have a total of 17634
wafer stacks.
Month 9
I added a furnace in this month. I have a total of 18188 wafer stacks.
25. Month 10
I added shift to all the operators in this month. I have a total of 23077 wafer stacks.
Month 11
I added two more furnaces in this month. I have a total of 31158 wafer stacks.
Month 12
I added one more wire saw in this month. I have a total of 31322 wafer stacks which seems to be
my best model.
Month 12 is the optimize model for me at 31322 wafer stacks. So my Final Model is my model
at MONTH 12.
27. Thus it is clear through the graph that my wafer stacks are being increasing from month 1 to
month 12. In Month 12, I got the maximum numbers of wafer stacks that is 31322 wafer stacks.
This would be a good model to use for the factory; the cost of the model will be minimum with
the maximum number of wafers produced. Also one can notice this factory only required seven
employees and still have very efficient production.
IMPLEMENTATION AND DOCUMENTATION
Hence, I made improvements on my base model on the every month basis by adding the
furnace, wire saw, paint booth, soaking station and sometimes giving shift to the operators, and
finally came up with the final model which is month 12 model where I have a total of 31322
wafer stacks. Thus, I recommend this model to New World Energy take to construct the 1.0
megawatt/month facility based on the 600K per month capital investment limit. I believe that I
have presented my results clearly, concisely, and convincingly. All the results have been clearly
understood, accepted, and used.
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WaferStacks
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Wafer Stacks VS Month
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