02_03_P2 Drawing the Current State Value Stream Map (VSM) - Acme Case Study
Summary
TLDRThe video covers a detailed case study on Acme Stamping Company, focusing on the production of steel instrument panel brackets for vehicle assembly. It explains the value stream mapping (VSM) process, emphasizing the flow of materials and information across departments like stamping, welding, and assembly. The presenter highlights the current state of Acme's operations, discussing inventory levels, cycle times, and inefficiencies in production, such as delays and imbalances between departments. The goal is to identify areas for improvement using lean manufacturing principles to optimize workflow and reduce lead times.
Takeaways
- 🔧 Acme Stamping Company produces steel instrument panel bracket assemblies for vehicle assembly plants, serving both left-hand and right-hand drive models.
- 🚚 The company's customer is the State Street Vehicle Assembly Plant, requiring 18,400 pieces per month, with 12,000 of type LH and 6,400 of type RH.
- 🏭 Acme operates in three main departments: Stamping, Welding, and Assembly, with daily shipments to the customer.
- 📦 Michigan Steel Company supplies raw material (steel coils) to Acme twice a week on Tuesdays and Thursdays.
- 📊 Acme's Production Control Department manages forecasts from the customer (90, 60, 30 days) and issues weekly schedules for internal departments and six-week forecasts to suppliers.
- ⏳ Stamping department has an automated 200-ton press with a cycle time of one second, but with a 5-day inventory backlog before processing.
- ⚙️ The welding workstations have manual processes, with varying cycle times (39 and 46 seconds), and accumulated inventory between departments creates inefficiencies.
- 🛠️ The assembly workstations have cycle times of 62 and 40 seconds, and despite 100% reliability, there's significant inventory buildup before assembly.
- 📈 The value-added time is just 188 seconds, compared to a total flow time of 23.6 days, indicating significant inefficiencies and delays in the system.
- 🔍 There is considerable imbalance (mura) in the system, with excessive work-in-process inventory and cycle time differences between departments, leading to waste and inefficiency.
Q & A
What is the main focus of the Acme Stamping case study?
-The case study focuses on Acme Stamping Company, which produces steel instrument panel bracket assemblies for vehicle assembly plants. The analysis involves creating a current Value Stream Map (VSM) to identify inefficiencies in the production process.
What are the key departments involved in Acme’s production process?
-The key departments in Acme's production process are Stamping, Welding, and Assembly. These departments are responsible for different stages of the manufacturing process.
Who supplies the steel coils to Acme, and how frequently are they delivered?
-The steel coils are supplied by Michigan Steel Company, and deliveries are made twice a week, on Tuesdays and Thursdays.
What is the daily customer requirement from Acme Stamping, and how is it structured?
-The customer, State Street Vehicle Assembly Plant, requires 18,400 pieces per month, which includes 12,000 left-hand brackets and 6,400 right-hand brackets. The components are shipped daily, with 20 brackets in a tray and up to 10 trays on a pallet.
How does Acme’s production control department coordinate with both its suppliers and customers?
-Acme’s production control department coordinates with customers by receiving 90, 60, and 30-day forecasts and daily firm orders. It communicates six-week forecasts and weekly confirmed orders to Michigan Steel Company, their supplier. The department also issues weekly build schedules to Acme’s production departments.
What are the cycle times and machine reliability rates for the stamping and welding processes?
-The stamping machine has a cycle time of 1 second and a reliability (uptime) of 85%. The first welding workstation has a cycle time of 39 seconds with 100% reliability, while the second has a cycle time of 46 seconds and 80% reliability.
How much inventory is observed between the stamping and welding stages?
-Before the stamping process, there are five days' worth of steel coils. After stamping, there are 4,600 pieces of type LH and 2,400 pieces of type RH waiting to be spot welded.
What are the main issues identified in Acme’s production process?
-The main issues in Acme’s production process include excessive waiting times and queues between processes, leading to high work-in-process inventory and low inventory turnover. There is a significant contrast between the long product lead time (23.6 days) and the short value-adding time (188 seconds).
What is the total product lead time at Acme, and how does it compare to the value-adding time?
-The total product lead time within Acme’s factory is 23.6 days. In contrast, the value-adding time (the time spent on actual productive work) is only 188 seconds, highlighting inefficiencies in the process.
What lean tools could be used to improve Acme’s production process?
-Lean tools such as Value Stream Mapping (VSM) can be used to identify waste (muda), imbalance (mura), and overburden (muri) in the system. Acme’s production process could benefit from reducing work-in-process inventory, balancing cycle times, and improving material flow between departments.
Outlines
🔍 Introduction to Acme Stamping Case Study
In this opening segment, the speaker introduces the Acme Stamping case study. The focus is on producing components for vehicle assembly plants, specifically steel instrument panel brackets in left-hand and right-hand versions. The company works with three departments: stamping, welding, and assembly. The steel is supplied by Michigan Steel Company twice a week, while the State Street assembly plant, the customer, requires 18,400 pieces per month. The production operates on two shifts, and manual processes pause for breaks.
📊 Production Control and Forecasting
This section explains Acme's production control system, which coordinates between the customer, supplier, and internal departments. The customer provides 90-, 60-, and 30-day forecasts, and daily confirmed orders. These are entered into a materials requirement planning (MRP) system, which issues six-week forecasts to Michigan Steel. Weekly schedules are sent to Acme’s internal departments. The discussion covers the necessity of ERP software for efficient coordination and the key role of the production control department in balancing inventory and production.
🛠 Detailed Breakdown of Acme’s Departments
This paragraph dives into the operational specifics of the stamping, welding, and assembly departments. Key metrics like cycle times, changeover times, and machine reliability are provided. The stamping department uses a 200-ton press, while spot welding and assembly processes are manual. Observed inventories and production outputs are noted, emphasizing the differences in efficiency and reliability across the various workstations. The shipping department stages products for daily shipment to the customer.
📦 Visualizing Acme’s Current State with Value Stream Mapping
The speaker begins outlining how to create a current state value stream map (VSM) for Acme. The map depicts the customer, supplier, production processes, and inventory levels between processes. Details of inventory and production timing are provided for each department. The speaker stresses the importance of accurate data collection for building the VSM and explains the symbols used to represent processes, inventory, and material flow in the diagram.
⏱ Calculating Lead Time and Process Efficiency
This section covers how to calculate lead time and work-in-process inventory in terms of days. For instance, the inventory between stamping and welding workstations is 7.6 days' worth of production. The total lead time from raw material to finished product is calculated to be 23.6 days, with only 188 seconds of actual value-adding time. The contrast between available time and value-adding time highlights inefficiencies, such as excess waiting and queue time between processes.
⚙️ Identifying Imbalance and Waste in Acme’s Production
The speaker wraps up by identifying areas of waste (muda), imbalance (mura), and overburden (muri) within Acme’s production. Disparities between cycle times across departments cause bottlenecks, leading to inefficient inventory turnover. The speaker suggests that the assembly department may be overworked due to higher cycle times and concludes with the need for further analysis to reduce waste and improve the production flow. The video description offers a link to the future state VSM.
Mindmap
Keywords
💡Value Stream Mapping (VSM)
💡Acme Stamping Company
💡Customer Requirements
💡Cycle Time
💡Changeover Time
💡Inventory
💡Production Control Department
💡Lead Time
💡Supplier
💡Uptime/Reliability
Highlights
Acme Stamping produces steel instrument panel bracket assemblies for both left-hand and right-hand drive versions of an automobile.
The customer is the State Street Vehicle Assembly Plant, which requires 18,400 pieces per month, broken down into 12,000 left-hand and 6,400 right-hand drive brackets.
Acme operates three departments: Stamping, Welding, and Assembly, with products shipped daily to the customer.
Michigan Steel Company supplies raw materials to Acme, delivering steel coils twice a week, on Tuesdays and Thursdays.
The production control department manages both supplier and customer interactions, using an MRP system to coordinate activities.
Acme receives 90, 60, and 30-day forecasts from the customer and sends six-week forecasts to the supplier.
The Stamping process uses an automated 200-ton press with a cycle time of one second and a changeover time of one hour. Machine reliability is 85%.
Spot welding processes (two workstations) have manual operations with varying cycle times (39 and 46 seconds) and 100% and 80% reliability, respectively.
Assembly workstations have cycle times of 62 and 40 seconds with no changeover time, and both have 100% reliability.
Acme has significant work-in-progress (WIP) inventory before and between processes, indicating inefficiency in material flow.
The product lead time, from raw material to finished product, is 23.6 days, but the value-added time is only 188 seconds.
A notable imbalance exists between the cycle times of different departments, leading to inefficiencies and potential bottlenecks in production.
There is a large amount of waste (Muda) in the system, with substantial waiting time and queues between processes.
The total available time at each workstation is 27,600 seconds, compared to the minimal value-adding time, reflecting significant unused capacity.
The current state Value Stream Map (VSM) reveals several areas for improvement, with potential focus on reducing waste and improving inventory turnover.
Transcripts
welcome back
this session we will uh discuss acme
stamping case study
and we will draw current vsm for acme
stamping
so first we will go through the
available information
and i will request you to highlight or
note down
important information so that you have
that
information with you once we draw the
current state
we asm so acme stamping company produces
several components for vehicle assembly
plants
this case concerns one product family a
steel instrument panel bracket assembly
in two types one is for left hand
and right hand drive versions of the
same automobile model
these components are sent to the state
street vehicle assembly plant
that is the customer so
basically there are three departments in
acme they are stamping
welding and assembly and the components
are
then staged and shipped to the vehicle
assembly plant on
a daily basis and we will go through
this information
of change over time later the steel
coils are supplied by michigan steel
company so that is the
supplier for acme and it supplies
the steel coils at twice a week
on tuesday and thursday then we have the
customer requirements or the
requirements of the
state street uh vehicle assembly plant
so
it requires 18 400
pieces per month out of which 12 000 per
month of type lh
and 6400 per month of type rh
customer plant operates on two ships
with overtime if necessary
pelletized returnable tray packaging
with
20 brackets in a tray and up to 10
trays on a pallet the customer orders in
multiples
of trays and there are 20 brackets in a
tray or
in other words there are 200 brackets
on a pallet one daily shipment
to the assembly plant by a truck
now the work time of acme
20 days in a month two shifts operation
in all production departments
eight hours every shift with overtime if
necessary and
two ten minutes breaks during each shift
manual processes stopped during breaks
now acme production control department
that is actually the central department
in this system because it coordinates
with both customer and supplier as well
as different departments of acme
so this department receives
a 90 60 and 30 day forecasts
from the customer and enters them to
materials requirement planning system
it issues six-week forecasts to michigan
steel company
via mrp that is the supplier so
receiving information from a customer on
one side and
and then and giving information
to the supplier on the other side
so it squares it secures coil steel
by weekly order release to michigan
steel company so there is a weekly order
to the supplier to supply the
steel coil it receives daily
firm order from the state street or
or the customer so apart from these
forecasts
there is a daily confirmed order from
the
customer as well so this production
control department
generates mrp based weekly
departmental requirements based upon
customer order
work in process inventory levels finish
good inventory levels and anticipated
scrap and downtime
so you can see there is a lot of
different difference in the time unit so
forecasts from the customer are received
based on
three months two months and one month
period
the forecast issued to the supplier
is for six weeks
then the instructions
or production requirements actually for
the internal departments of acme are
delivered on weekly basis so it's very
important to have some software in this
case they are having erp
to effectively coordinate all these
activities
so this mrp
system actually is used to issue weekly
build schedule to stamping welding and
assembly processes that are the
departments of acme
and it also issues daily shipping
schedule to the shipping department
because the products are shipped
daily to the customer
production processes as there are three
departments so first we have stamping
the press makes parts for many acme
products
it's an automated 200 ton press with
automatic material feed now these
pieces of information are important
the cycle time for stamping is one
second
so 60 pieces per minute change over time
is one hour
and machine reliability is 85
or uptime is 85
observed inventory is also important so
we have five days of coils before
stamping
4 600 pieces of type lh
finished stamping and 2 400
pieces of type rh finish stamping so
this is the inventory before
the stamping machine and this is the
inventory that
is produced by the stamping machine
and still is waiting for
spot welding now spot welding
workstation one
is dedicated to this product family it's
a manual process with one operator
cycle time is 39 seconds change over
time is
10 minutes reliability is 100 and
absorbed inventory
is 1100 pieces of lh and 600
pieces of type rh
then we have spot welding workstation 2
this is also dedicated to this product
family
it's also manual process with one
operator but the cycle time is different
it is 46 seconds
change over time is the same 10 minutes
reliability here is 80
and inventory observed for this process
is 1600 pieces of type lh and 850 pieces
of type rh
then there is assembly workstation one
this is also manual process with one
operator cycle time is 62 seconds
there is no change over time because
this is a manual process
reliability is 100 percent and observe
inventory is 1200 pieces of type lh and
640 of type rh
an assembly workstation 2 is also
dedicated to this product family
manual process with one operator cycle
time here is 40 seconds
change over time is none because it's a
manual process reliability is hundred
percent and observing
20 is 27 100 pieces of type legend
1440 pieces of type rh
and finally we have the shipping
department it removes parts from finnish
goods warehouse and stages them for
track shipment of the customer now we
will draw the current
state vsm so again we will draw
the customer on the
right side upper right corner so this is
the symbol for
the customer so that is state street
assembly plant
and then we have the data box that
specifies the information
uh the requirements for the customer so
18 400 pieces per month
12 000 of type l and 6400 type r
the product is accounted in terms of
trays
so there are 20 pieces in a tray and
this plant customer's plant operates in
two ships
then we draw the
processes for
so as we saw there is a five days
inventory before stamping department so
this is the icon for the process name of
the process
and then this is the data box specifying
the data related to stamping so cycle
time of one second change over time of
one hour uptime or reliability of 85
percent
and this is the time for for the two
shifts available
and ep stand for every part every two
weeks
this is the inventory between stamping
and
welding station one and this was the
observed inventory after stamping
and these are the details for for
welding workstation one i'm not reading
them because
i just saw this information on the
previous slides
again the observer inventory after
welding station
one and this is the the process icon for
welding workstation two and this is the
information about welding workstation
two
and same is about assembly workstation
one
and assembly workstation two and finally
we have the shipping department
and below this inventory icon
we have written the inventory that is
produced by this process so this is the
inventory actually produced by assembly
uh workstation two
then we we draw the
supplier so again
the icon for the outside organizations
so that is the same as it was for the
customer
so the material supplies is in
in 500 feet coils and it is supplied
every tuesday and thursday so you could
see
it is mentioned on this shipment icon
the finished products actually supply to
the customers are supplied daily
but the raw material is supplied by the
supplier to acme is
twice a week on tuesday and thursday so
we can have this filled arrow or
a hollow arrow to show the movement
of material from supplier to the
organization or
or the movement of finished products
from the organization to the customer
so the supplier of raw material is
identified with the factory icon as i
mentioned
it in this case they deliver 500
foot coils and a track icon and uh
and a broad arrow indicate movement of
finished goods to the customer and raw
material to the site as i mentioned
so finally we draw the production
control department
and here you will see a lot of
information flow so this is
again the symbol for for a department or
a process to
do rectangles to rectangular boxes
joined together
so you could see that there is a 1960
and 30-day forecast
from the customer to the production
control department
and there is a daily confirmed order
from
other customers to acme through its
production control department this
production control department
delivers six-week forecasts to its
supplier that is michigan steel company
as well as weekly confirmed order
to the supplier and there are
weekly build schedules and weekly
requirements
communicated from this production
control department to all departments
of acme so that is the weekly schedule
and here actually the head of the arrow
is missing
sorry for that so this is the push arrow
so that is showing the material flow
between departments of acme along with
this symbol for
inventory and again below
these processes are the data boxes for
for each of the process
so push arrow symbol of inventory
and the amount of inventory so this is
uh almost the complete vsm we are
missing just timeline so far
so moving from right
the customer its
requirements then flow of information so
this symbol
is for electronic information flow
and these symbols are for
manual information flow
and then on the on the left side we have
the
supplier and these are the departments
of acme and flow is shown from left to
right
now finally the timeline
so there was a five days of inventory
uh before the stamping department the
cycle time of stamping was one
second the cycle time for welding
station one was 39 for welding station
two it was 46
assembly one it was 62 and for assembly
two it was 40 seconds
now we have simply converted the
inventory between different processes
into into days so
for example here the requirement for
the customer was 18 400 pieces per month
so
that 18 400 pieces per month and
and the organization works 20 days a
month so 18
400 over
20 that will be equal to 920
pieces per day so that is the daily
requirement
of of state street assembly plant
now the work in process inventory
between stamping and
the welding station one is
4600 plus 2400
so that turns out to be 000 so that
divided by 920 will give us
the work work in process inventory in
terms of days so that will be equal to
4 600 plus 2400
divided by 920
that we had here so that will turn out
to be
7.6
7.6 so this inventory of 7000
brackets between stamping and welding
station 1 is worth
an inventory of 7.6 days
similarly between welding station 1 and
welding station 2
we have 1100 plus 600 so that is 1700
divided by 920 so that is
equal to 1.88
so the inventory of 1700
brackets between welding station 1 and
world welding station 2
is equivalent to an inventory of 1.8
days
and similarly we can do the same for
for this work in process inventory so
that will be equal to
2450 so 1600
plus 850
divided by 920 so that will be equal to
2.66 or about 2.7
and similarly this one uh
18 040 divided by 920
will be equal to a work work in process
inventive worth
two days and finally
we have this 2700 sorry 2700
plus 1440 divided by 920
so that will be equal to 4.5
so if we add these together they all
turn out to be 23.6 days so in other
words we can say that
the raw material starting from here
till this final process of
assembly before shipping
takes 23.6 days so the
product lead time actually total flow
time
of the product within the factory is
23.6 days
and more importantly here is that the
value adding time is just
188 seconds so that is a big
big contrast so if you if you make some
calculations
so we saw somewhere here actually
that the available time at each
workstation is
actually two shifts so that turns out to
be about
this 27 600 seconds
but the value-adding time throughout the
whole
value stream is just 188 seconds
within the organization within acme it
is just 188 seconds
while we have 27 600 seconds available
at each workstation so in simple words
a lot of time is actually being wasted
between processes
there is a lot of weight or a lot of q
is there
between processes so the time spent
within the organization is too much
and the value adding time is too small
so
this will also result in actually low
inventory turnover so that is actually
how fast the
raw material
starting from here and these these coils
is converted into the finished product
here so the faster it is done the higher
is the inventory turnover the slower it
is done the lower is invented turnover
so we can think about it we can
analyze this system using different
tools of lean
and see how we can improve with these
processes because there is
a lot of imbalance so you can see
actually
there is a lot of
mura as well in this case
there is a lot of weight there there is
a lot of q
but there is a lot of unbalance uh
there is a lot of imbalance in the
system as well so a lot of work in
process inventory here
relatively less here but still it is a
lot
and of course you can see the difference
of
cycle time here as well one second in
stamping but 39
in welding station 1 and 46 62 40 so
there is
a lot of mura in this system as well
so maybe practically speaking the
assembly department
one may have to work harder because of
the higher
cycle time as compared to others so
eventually
we may have mori in the system as well
so the slower department will have to
work harder
in order to meet the customer
requirements
so we can further analyze it
and see where improvements can be made
and how we can move from this current
state to the future state vsm
and you can follow the video given in
the description actually
to see how the future state for acme
was drawn thank you very much
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