Micron Confidential

Micron NUS-ISE
Business Analytics Case
Competition 2024
Question

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Micron Confidential

Contents
Introduction .................................................................................................................................................. 2
Background ................................................................................................................................................... 3
Disclosure ...................................................................................................................................................... 3
Challenge....................................................................................................................................................... 4
Question 1: ................................................................................................................................................ 4
Part a) .................................................................................................................................................... 6
Part b).................................................................................................................................................... 6
Part c) .................................................................................................................................................... 6
Question 2: ................................................................................................................................................ 7
Part a) .................................................................................................................................................. 10
Part b).................................................................................................................................................. 10

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Micron Confidential

Introduction
Digital technologies such as Smart Devices, Internet of Things (IOT) and Artificial Intelligence
(AI) are changing the world we live in from the way we connect with each other, how we make
purchases, and even how we commute. Data is the new currency, and it is all around us, in our
connected devices, machines, and gadgets. It is captured in data centers, stored in the cloud,
and surged through networks. 330 quintillion (1018) bytes of data created per day, and it is
growing exponentially year by year. And memory chips are the key enablers in moving,
processing, collecting, storing, and sharing data, empowering many of the cutting-edge digital
devices we use today and the technologies that are changing our life.

Micron is a world leader in innovative memory solutions that transform how the world uses
information to enrich life. Backed by more than 45 years of technology leadership, Micron
offers the industry’s broadest and most cutting-edge technologies in Memory and Storage,
enabling disruptive trends in key market segments like mobile, data center, client, consumer,
industrial, graphics, automotive, and networking. Singapore is home to Micron’s largest
manufacturing footprint with three facilities and a technology center supporting innovation
globally for the company. Micron continues to expand its presence here in Singapore, serving as
the base of worldwide operations.

Applica ons of Micron Memory Chips

From 5G smartphones to the AI-enabled cloud, memory fuels everything that computes and is
essential to growing the data economy. To address 2030-era demand for memory, Micron plans
to invest more than $150 billion globally in manufacturing and R&D over the next decade.

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Micron Confidential

Micron Semiconductor, as one of major suppliers of Memory and Storage solutions, has
invested heavily in expanding its own capacity through building new plants. Micron
Semiconductor have also expanded its existing plants, including a two-time expansion in
Singapore in 2016 and 2019, and a recent announcement to expand in Boise, US, to accelerate
the production ramp of advanced memory technology. In 2022, Micron Semiconductor has also
announced to invest up to $100 billion to build a brand new Mega-fab in Central New York, US.

Background
Among the many infrastructures that are required to support Micron’s manufacturing
operations and expansion, one of them is to manage huge variety of material usage
requirement that are used in processing Micron chips at every single processing step across
varying products. This complex and constantly evolving usage needs to be planned and
managed with changing production plans to provide material forecast to suppliers. The
challenge to Micron’s team is optimize the planning and cost of materials by creating an
accurate material forecast to ensure just in time delivery with optimal inventory level onsite
that will not incur any material excess that can lead to high cost incurred or worse, shortages
that cause production disruption.

In this Business Analytics Case Competition, we will take a deeper dive into the material
planning to strategically meet the increasing demands of our production expansions.

Disclosure
In this challenge, all materials, figures, and numbers used are strictly arbitrary and have no
reference to actual production in Micron Technology, Inc.

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Challenge
Question 1:
As a Material Planning Engineer, you are tasked to provide material forecast for supply management
team to negotiate and purchase necessary materials for production. The high complexity of the
processes in semiconductor wafer production often causes the forecasting of material requirement to
be challenging. Equipped with your knowledge in planning and forecasting, you are tasked to come up
with a model to forecast the material usage, by utilizing data including but not limited to the process
and/or material specifications given by process team, and historical actual usage of the material.

Your answers will be judged based on its Accuracy, Insights, and Creativity. Please provide all written
answers in a report document in PDF format.

Table 1.1: Definition of Terms

Attribute Definition
Lot 1 lot refers to 1 unit of product
Wafer 1 wafer refers to 1 unit of silicon disc within a lot
Load size Number of wafers in a batch
Usage Amount of material used to process a lot in a Step
Inventory Amount of material stored on site to standby for production use
Batch Life Number of batches that can be processed before the chemicals have to be
replenished with fresh chemical
Reclaim % Proportion of materials that can be reclaimed and reused
Chemical Life The elapsed time before chemicals must be replenished with fresh chemicals
Wafer Projection Projection of wafer demand in the production plan
Forecast Total amount of material required by all steps in a specified period

Wafer Cleaning Process

One of the materials required for production is Sulphuric Acid (H2SO4). Sulphuric Acid (H2SO4) is used in
the wafer cleaning process, where batch of wafers are “rinsed” in a tank. To put it simply, you can think
of it like washing plates in the kitchen sink, where the Sulphuric Acid (H2SO4) acts as the water. This
process is sensitive to the concentration of the chemicals in the tank. When the concentration falls
below acceptable level, the chemicals must be discarded. The batch life and chemical life of the material
determine when the chemical must be discarded and replenished with fresh chemical. Before
replenishment, a portion of the chemicals can be reclaimed in a container and get recycled to be mixed
with fresh chemicals to top up the tank (this is determined by the reclaim efficiency).

** Chemicals in the tank must be dumped and replaced upon reaching batch life or chemical life,
whichever earlier, except for the reclaimed portion of the chemicals that is collected and can be
reused to top up the next tank. Either batch life or chemical life will determine how much chemical is
required in a week, with the assumption that the wafer processing is evenly distributed across 24 hours
a day, 7 days a week.

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Micron Confidential

Figure 1.1 Simple illustration of wafer cleaning process in the tank

Wafer Cleaning Process

Batch of
Wafers

Chemical
Tank
Recycle Container

Figure 1.2 Illustration of Chemical Replenishment

Chemical Replenishment
Recycle Container

Fresh Chemicals

Chemical
Tank

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Micron Confidential

Part a)
You managed to gather additional information from the Process team, Equipment team, and Production
Planning team to help you with the forecasting of the Sulphuric Acid (H2SO4) usage.

Table 1.2: The current H2SO4 needed to produce 1 batch of product A and B.

Product Batch Life Loadsize (wafers)

A 5 to 7 35 to 38
B 7 to 8 45 to 52

Table 1.3: Wafer Projection for the next 10 weeks

Product Wk 1 Wk 2 Wk 3 Wk 4 Wk 5 Wk 6 Wk 7 Wk 8 Wk 9 Wk 10
A 3289 3566 2358 2951 2152 973 2453 2314 2347 2765
B 2100 2409 4090 1874 3893 3973 3615 3541 2900 2602

The equipment has a tank size of 80L and can be used to produce both product A and B. Historical data
shows that the reclaim efficiency of Sulphuric Acid (H2SO4) ranges from 4% to 9%, and the chemical life
for Sulphuric Acid (H2SO4) is 500 minutes.

Formulate a method to forecast Sulphuric Acid (H2SO4) and provide the forecast on the requirement for
Sulphuric Acid usage in the next 10 weeks by studying the sets of data. The forecast will help the team to
negotiate with the suppliers and ensure Micron has sufficient supply of the chemical for production. On
top of the final forecast number for each week, please also share the approach that you take to tackle
this challenge (Max 300 words).

Part b)
After running the production for the 5 weeks, you manage to obtain the information of the actual usage
of Sulphuric Acid for the first 5 weeks.

Table 1.4: Actual Usage after the first 5 weeks

Wk 1 Wk 2 Wk 3 Wk 4 Wk 5
Actual Usage (L) 1686 1998 1858 1870 1894

With the actual usage data and given a chance to regenerate the forecast for the remaining 5 weeks,
share how you would adjust your forecast by utilizing the historical usage data (Max 200 words)

Part c)
Given your experience in planning and forecasting for the usage in the short term, you are now tasked
to model for the longer-term planning for the Sulphuric Acid material.

With some of the lesson learnt through the experience in part 1a and 1b and through your own
research, share what are the key factors that should be considered for the long term planning and
inventory management of this material and how would you model in these factors (Max 500 words)

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Question 2:
As a Production Planning Engineer, you are tasked to develop a strategy to optimize the production plan
while considering multiple constraints and challenges in the line. Consider the scenario below:

For lot production, the fab can run different recipes, and each recipe will have a different processing
time, steps compatibility, and will require different materials combination and quantity. The fab has 3
equipments (Alpha, Beta, and Gamma) to process the lots. Below is the list of recipes that the fab can
choose to run on each equipment, its required processing time, and the steps compatibility.

There are multiple recipes to choose from to run each of the steps as shown in the table below.

Table 2.1: Recipe Selection

Step Recipe Selection

Step 1 A or B or D
Step 2 C or E
Step 3 B or D or E
Step 4 B or C
Step 5 A or C or D

Below is the list of recipe requirements, including its processing time and material usage.

Table 2.2: Recipe Processing Time Information

Processing
Recipe
Time
A 4 hrs
B 3 hrs
C 5 hrs
D 2 hrs
E 6 hrs

Each of the equipment has different capabilities to run different recipes, and any recipe switch within
the same equipment will require equipment downtime for chemical cleaning as shown below.

Table 2.3 Equipment Recipe Compatibility

Equipment Recipe
Alpha A, B, D, E
Beta B, C, E
Gamma A, C, D

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Table 2.4 Recipe Switch Equipment Downtime (in hours)

Recipe Switch A B C D E
A - 1 1 3 1
B 1 - 1 1 2
C 1 1 - 1 2
D 3 1 1 - 2
E 1 2 2 2 -

Table 2.5: Recipe Material Usage (per run)

Recipe Material X Usage (L) Y Usage (L) Z Usage (L)

A X 24 0 0
B Y 0 22 0
C X and Y 6 9 0
D X and Y and Z 20 15 6
E Y and Z 0 8 4

** Usage of materials X, Y and Z in table 2.5 are for 1 time process use and not per hour use. Materials
are consumed during the process.

Table 2.6: Material Supply Information per week (assume that unused material will expire and need to
be discarded each week)

Pricing Tier ($/L)

Material
0-50 L 51-500 L >500 L

X $200 $190 $175

Y $300 $275 $250

Z $240 $220 $205

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Micron Confidential

Below is an illustration example of lots processing across 24 hours based on the recipe that the
equipment is running.

Table 2.7: Illustration Example of Lots Processing

Equipment Alpha Equipment Beta Equipment Gamma

Recipe
A,B,D,E B,C,E A,C,D
Capability
Hours Lot Recipe Step Lot Recipe Step Lot Recipe Step
1 1 A 1 2 B 1 3 A 1
2 1 A 1 2 B 1 3 A 1
3 1 A 1 2 B 1 3 A 1
4 1 A 1 SWITCH SWITCH SWITCH 3 A 1
5 SWITCH SWITCH SWITCH 1 C 2 SWITCH SWITCH SWITCH
6 SWITCH SWITCH SWITCH 1 C 2 SWITCH SWITCH SWITCH
7 SWITCH SWITCH SWITCH 1 C 2 2 C 2
8 4 D 1 1 C 2 2 C 2
9 4 D 1 1 C 2 2 C 2
10 SWITCH SWITCH SWITCH SWITCH SWITCH SWITCH 2 C 2
11 SWITCH SWITCH SWITCH IDLE IDLE IDLE 2 C 2
12 1 B 3 2 B 3 3 C 2
13 1 B 3 2 B 3 3 C 2
14 1 B 3 2 B 3 3 C 2
15 1 B 4 SWITCH SWITCH SWITCH 3 C 2
16 1 B 4 SWITCH SWITCH SWITCH 3 C 2
17 1 B 4 4 E 2 2 C 4
18 SWITCH SWITCH SWITCH 4 E 2 2 C 4
19 SWITCH SWITCH SWITCH 4 E 2 2 C 4
20 1 D 5 4 E 2 2 C 4
21 1 D 5 4 E 2 2 C 4
22 5 D 1 4 E 2 2 C 5
23 5 D 1 IDLE IDLE IDLE 2 C 5
24 IDLE IDLE IDLE IDLE IDLE IDLE 2 C 5

Your answer should strictly adhere to the following constraints:

 A lot is required to run from Step 1 to Step 5 sequentially, after which it will be a finished product.
 Each recipe must run to completion for each lot for each step in the same equipment.
 A lot that has not completed the full Step 1-5 sequence will not count as a completed product
and thus will not be sellable at the end of the 168 hours.

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Part a)
List down all the constraints and restrictions that you need to adhere to before building the optimal
production plan.

Part b)
Assume the selling price of each completed lot to be $40,000.

Using the above information, propose an optimal production plan for 7 days (168 hours) that is most
profitable for the company (Do fill in the necessary answers that you obtained in the excel sheet
named “Answer Sheet” provided in the question folder)

Briefly explain your answers/approach (max 200 words)

Instructions when filling up Excel:

1. Input your solution with only "Lot Number", "Recipe Letter", "Step Number", "SWITCH", OR "IDLE".

2. Unused hours in equipment to be filled with "IDLE" for all "Lot", "Recipe" and "Step" respectively.

3. Do not merge the cells and fill it with any other letters or words.

4. Fill in the yellow cells with the usage of each Recipe and Material, number of completed Lots, and
calculate your revenue, cost, and profit over the 168 hours.

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