International Journal of Electrical, Electronics and Computer Systems, (IJEECS)
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VALUE STREAM ANALYSIS ON A PRINTED CIRCUIT BOARD
(PCB) PRODUCTION LINE
1
Arvind S, 2Syari S Nair
1,2
Department of Industrial Engineering & Management, M.G University, Kerala
Email: aravinds@gmail.com, syarinair@gmail.com
holds much potential for undetected waste. This project
looks at the assembly portion of a manufacturing facility
and shows how Lean Manufacturing can be applied to
improve these processes. The VSM tool is considered as
a functional method aimed at reorganizing production
system with the lean vision.
ABSTRACT- The possibility of lean implementation in a
high mix low volume industry is studied at an electronic
manufacturing firm. The aim is to analyze the production
process of one of the Printed Circuit Board (PCB)
production line and find out possibility of productivity and
lead time improvement. Value Stream Mapping is used to
check the current production flow of one product family of
PCB. VSM is a lean manufacturing tool that helps to
identify and remove seven deadly wastes. eVSM software is
used to draw the Current State Value Stream of the
production flow. This current state VSM is been analyzed
to identify all value added and non-value added activities.
Implementing flow using supermarket concept, TakT time
and pacemaker analysis are also carried out. It is found
that, by removing all non-value added activities and by
including flow and supermarket and pacemaker process at
each subassembly, considerable reduction in lead time is
possible. Based on these finding, a future state Value
Stream Mapping is been devised showing modified work
flow with improved matrices like lead time, less waste etc.
The changes needed to achieve the desired future state are
summarized.
Reducing the lead time of value streams through the
implementation of lean methodologies would help the
firm to increase current customer delivery challenges as
well to plan for increased demand in the future. Through
this thesis, an attempt is made to implement traditional
lean methods to a high mix low volume production
environment to prove that lean base concepts are
applicable and does produce improvement in this kind of
industry too.
II. METHOOLOGY
The research started by taking a tour of the plant and
observations were made on the shop floor and the entire
plant. Then discussions involving people from different
departments of the company were conducted, so that
further details of the current production process could be
obtained and discussed. Information regarding cycle
time, lead time, number of operators involved in each
process, amount of inventory and work-in progress
between processes were determined. Based on the
information gathered, a current state map was drawn
which depicts process flow, product flow, information
flow and communication flow. Takt time and cycle time
are also calculated. The data is then analyzed to see what
areas need improvement by identifying non-value added
activities that can be reduced and eliminated. Thereafter,
the current state map is expanded into future state map
followed by further discussions and analysis. Lean
Keywords – eVSM , High mix Low volume, Lean , Printed
Circuit Board, VSM
I. INTRODUCTION
As part of the growth plan of this electronic
manufacturing company, it is looking at implementing
lean in their facility so that they can accommodate more
orders without increasing resources or investing in more
machines. This study takes up production flow of one of
the PCB product family and analyzes value added and
non- value added activities using Value stream
management tool. It then suggests improvement areas,
especially better cycle time and inventory lead time. The
assembly section is usually the highest concentration of
labor in an electronics assembly plant, and therefore
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International Journal of Electrical, Electronics and Computer Systems, (IJEECS)
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techniques are suggested for improvising the product
flow, communication flow and information flow.

Data collection
In the study, data is collected through different means.
The prominent method is to visit the production plant,
walk through the length and breadth and observe
activities. Recording of original data related to flow is
done. An attempt is made to talk with the operators, QA
of each section as well as the production engineers.
Formal interview with engineers, operators, different
department members, line manager and production
manager are conducted. Studying the internal
documentation and previous quality data helps to get a
detailed picture as well like field observation. In
particular, quantitative data on lead and cycle times as
well as product specifications were collected, whereas
field observations resulted in both qualitative and
quantitative data (cycle time measurement).

Fig 1: One Process with matrices in VSM
Supplier loop, internal loop and Customer loop has to be
separately drawn

Based on the analysis above, different recommendations
are provided to improve from the current stage. Possible
results post lean implementation is highlighted.
Improvements in key matrices across states are
highlighted. Ways to remove different wastes are
discussed in detail. How each non value added activity
can be eliminated is looked into in details. Post
elimination of waste and non-value added activates, the
improved lead time, machine efficiency etc are shown.
After implementing the changes like continuous flow
and pacemaker process, improvements in key matrices
are noted. A future value stream map including all the
changes devised above is been drawn
Product Family Selection
All the products are analyzed for its different process
stages for the purpose of identifying the ones going
through similar process stages. Not only the process
stages matters, but lead times across stages need to be
comparable. After careful and time taking study and
observation of about 10 to 13 production lines, DSM 3
series of products are found to be suitable for lean
implementation .The reason being, all product variations
goes through a set of sub processes with hardly any
variations. The difference between lead times taken at
each stage between each product variety is within a
comparable limit as well. So combining them and
brining then under one umbrella is possible,

Recommendations for a future state map
III. ANALYSIS
Different products being manufactured at the pant are
studied and their process stages re-recorded It is seen
that, DSM Part Number 1080-0594-01 to 06 follow
similar process stages from row material receiving till
packing and shipping. It is also observed that, the
difference in lead time across DSM 3 products family
products are negligible compared to other products
analyzed here.
Create a Current State VSM using eVSM
Current State Map depicts the AS-IS material and
information flow of DSM 3 production. It also depicts
major matrices of importance across each sub process
level and a cross sub assembly levels. Supplier details
and customer details are captured. eVSM software is
used to draw current state VSM. eVSM is built on top of
Microsoft Visio 2013. This software has templates
specific with Value Stream mapping symbols. The
current state material and information flow can be
mapped by dragging and dropping appropriate symbols
into the drawing pane and by including values for key
performance parameters. After inserting the appropriate
symbols, collected data as well as the correct names for
each operation is included. After inserting the correct
cycle times, the total cycle time for the specific VSM is
calculated by adding up the individual cycle times
together.

Current State Processes and Statistics
Production of DSM 3 consists of a chain of processes to
convert the row material to finished good product. The
production steps of DSM 3 product family is shown
below. The process starts when row materials in cartons
in packed state, are been delivered to the shop floor for
SMD and delivered to the kitting area for Through Hole.
Any pre- processing to be done on the components like
cutting the edges etc for through hole components is to
done at kitting area. Once order to make is been given to
shop floor, loading/unloading team comes to the shop
floor , unpacks the cartons of components and starts
loading the components to the pick and place machine.
Operators do setup for Screen Printing, Pick & Place
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International Journal of Electrical, Electronics and Computer Systems, (IJEECS)
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and Reflow oven machines. Appropriate programs have
to be loaded to all these machines.
located at 1 KM distance from the plant plot. Only when
kit pulling is initiated by the planning department, the
boxes of row materials for that order would be retrieved
from the warehouse to the kitting area. The customer
sends separate boxes for SMD and Through Hole area.
Supplier loop is shown in Fig 3.
ICT, FCT and Packing is located in a different building,
approximately 400 meters away from the production
floor. Work in progress Printed Circuit Boards need to
be transported to the building where testing and packing
team is located. Packed PCBs in cartons, ready to be
shipped would be moved to 2nd floor of the same
building, from where it will be picked by shipping team
by 2 PM every day.

Current state value stream
Current state of DSM 3 product family is drawn after
considering both material and information flow between
and through the production line. The value stream
includes the value adding and non-value adding
activities that are required to bring a product from raw
material through delivery to the customer.

Fig 3: Supplier Loop
Customer Loop of VSM

Customer has projected a monthly demand of 10000
pieces. There are slight variations across months.
Monthly average delivery of finished goods to
customers is 8000 to 10000 pieces. The finished goods
are delivered as pallets. One pallet contains 720 units of
finished good. This many printed circuit boards are
usually packed in 12 boxes, where each box contains 60
pieces of finished goods. In one week customer expects
1 pallet to be delivered. The finished goods are stored in
warehouses. The cartons of 60 pieces would be
delivered to customer on a daily basis. Daily Target is to
send 2 boxes full or cartons, so that by 6 days 12 cartons
can be sent.
Internal loop is given in Fig 4. Material Requirement
Planning (MRP) and Master Production Schedule (MPS)
runs twice monthly. Monthly sales plan will be provided
by Program Management Team.6 months forecast also
would be given .Inventory availability report is
generated based on the sales forecast and procurement
order would be generated and would be send to SCM
team. SCM team creates purchase orders and sends
through email to suppliers. For confirmed orders,
product build option is run which will generate Dynamic
shortage list. Based on this Work Order would be
generated. Work order status can be ‘Released against a
customer order’, or Firm planned is where plan is
confirmed or planned. Planned is system generated and
deleted orders. Once an order is the status changes to
‘Production Plan release ‘, a Kit loading Plan would be
generated. A daily production plan gets generated which
would be communicated to the production team. There
is a separate plan called Machine loading to finished
good plan. Management information system for
reporting is also gets generated.
Takt Time =
Effective work time per shift /
Customer requirements per shift TT =
Available
production time / Total daily Quantity required.
Takt Time is calculated as 3 minutes. In order to
achieve standard output in each shift, production crew
has to produce 1 piece of PCB in 3 minutes. Customer is
buying this product at a rate of one every 3 minutes.
Customer loop of VSM is shown in fig.2
The analysis is based on the three lean principles:
specify value, identify value stream and make value
flow. The analysis starts with an understanding of how
customers perceive value. Next, visualize the value
stream of DSM 3 flows including the analysis of time
frame and ownership in the order fulfillment process.
The main focus will be on the waste identification in the
flow and the solutions to reduce the influence of
identified wastes. Furthermore, possible lead time
reduction due to waste and bottleneck elimination will
be calculated. Analysis on making the process more lean
and continuous will be done. In addition, lot size
analysis would also be conducted
Fig 2 : Customer Loop

Internal Loop of VSM
Supplier Loop of VSM
Entire components per order is been delivered to the
warehouse by the supplier directly. The warehouse is
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ISSN (Online): 2347-2820, Volume -1, Issue-2, 2013
65
International Journal of Electrical, Electronics and Computer Systems, (IJEECS)
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DATE
TITLE
4/14/2013
by machine (SMD), the possibilities of frequent errors
are not there. So inspection based on a sampling need to
be considered. So 100% inspection is not needed.
Current State Value Stream
FILENAME
CURRENT VALUE STREAM.VSDX DESCRIPTION
Current state VSM of Printed Circuit Board Production Flow
REVISED
4/24/2013
A130
Supply Chain
Management
all
Planning and Control Department
Program Management
Supplier
Customer
Ways to remove waste:
Customer
Item
xx
Demand
Day
Warehouse
Reduce set up time: To avoid searching time and to
reduce waiting time to load reels to machines, reels need
to be colored or use colored label to differentiate
between 100s of components. Component value
checking is performed twice for all components, by
loading team & by QA. QA team can check for
sampling rather than 100% validation. All QA check
needs to be done in parallel to loading to the machine
time. Make trays of 50 PCBs already before screen
printing gets finished for one batch.
Weekly Production Schedule
Row Materials
In process Circult
Testing ( ICT)
Production Through hole
Production SMD
Functional Testing
( FCT)
Final Inspection
Packing
Row Materials
A020
1
A110
Loading
5
Machine Time 0 Min
1
2
Machine Time 40 Sec
Manual Time 5 Hr
Manual Time 10 Sec
Process Lead
50 Sec
Time
StUp
Setups 10
Min
Day
Wait 5
Min
Transport
0 Min
Time
Utilization 1 %
Utilization 1 %
operators 5 1to10
operators 2 +1 1to10
shift
N/A 1to10
Lot Size 50
Ite
m
1
Pick and Place
Process Lead
5 Hr
Time
StUp
Setups 15
Min
Day
Wait 0
Min
Transport
0 Min
Time
shift
A140
Screen Printing
2
A160
1
A170
Reflow Oven
2
Machine Time 1.8 Min
Machine Time 7 Min
1
A180
1
A190
1
Reflow Inspection
Manual Stuffing
Wave Soldering
3
5
2
2
1
3
1
1 A240
1 A250
Download
1
1
1
RF
1
A270
1
Sourcing
Burning
1
1
1
A280
1
4
1
Packing
1
Machine Time 12 Min Machine Time 5 Min Machine Time 8 Min
Machine Time 6 Hr
Manual Time 5 Min
Manual Time 2 Min
Manual Time 7 Min
Manual Time 5 Min
Manual Time 1 Min
Manual Time 1 Min
Manual Time 1 Hr
Manual Time 1 Min
Manual Time 8 Min
Manual Time 3.5 Min
Process Lead
5 Min
Time
StUp
Setups 50
Min
Day
Wait 0
Min
Transport
1 Min
Time
Process Lead
5 Min
Time
StUp
Setups 5
Min
Process Lead
7 Min
Time
StUp
Setups 5
Min
Process Lead
5 Min
Time
StUp
Setups 5
Min
Process Lead
2 Min
Time
StUp
Setups 3
Min
Process Lead
Process Lead
Process Lead
13 Min
6 Min
9 Min Process Lead 7 Hr
Time
Time
Time
Time
StUp
StUp
StUp
StUp
Setups 0
Setups 0
Setups 0
Setups 20
Min
Min
Min
Min
Process Lead
6 Min
Time
StUp
Setups 1
Min
Process Lead
8 Min
Time
StUp
Setups 1
Min
Process Lead
3.5 Min
Time
StUp
Setups 3
Min
Transport
1 Min
Time
Transport
3 Min
Time
Transport
1 Min
Time
Transport
2 Min
Time
Transport
0 Min
Time
Transport
0 Min
Time
Transport
0 Min
Time
Transport
2 Min
Time
Transport
1 Min
Time
Transport
1 Min
Time
Transport
1 Min
Time
Utilization 1 %
Utilization 1 %
Utilization 1 %
Utilization o %
Utilization 1 %
Utilization 1 %
Utilization 1 %
Utilization 1 %
Utilization 1 %
Utilization 1 %
Utilization 1 %
Utilization 1 %
Utilization 1 %
Utilization 1 %
Utilization 1 %
operators 2 1to10
operators 2 1to10
operators 3 1to10
operators 5 1to10
operators 2 1to10
operators 2 1to10
operators 3 1to10
operators 1 1to10
operators 1 1to10
operators 1 1to10
operators 1 1to10
operators 1 1to10
operators 1 1to10
operators 4 1to10
operators 1 1to10
1 at a time
shift
1 1to10
shift
2 1to10
shift
1 1to10
shift
3 1to10
shift
0 Min
2 1to10
Wait
shift
0 Min
2 1to10
Wait
shift
0 Min
2 1to10
Wait
shift
0 Min
3 1to10
Manual Time 1 Min
Wait
shift
Manual Time 1 Min
0 Min
3 1to10
Wait
shift
0 Min
3 1to10
Wait
shift
0 Min
3 1to10
Machine Time 5 Min
A290
Final Inspection
Manual Time 10 Min
Wait
Machine Time 1 Min
1 A260
Analog
Process Lead
10 Min
Time
StUp
Setups 5
Min
Day
Wait 1
Min
Transport
1 Min
Time
2 Min
Machine Time 0 Min
A230
ICT
Manual Time 0 Min
Wait
Machine Time 0 Min
A220
Final Inspection
Process Lead
7 Min
Time
StUp
Setups 30
Min
Day
Wait 1
Min
Transport
1 Min
Time
3 1to10
Machine Time 3 Min
A210
Manual Time 2 Min
shift
Machine Time o Min
1
Post Wave Soldering
Inspection
Process Lead
3.8 Min
Time
StUp
Setups 3.5
Hr
Day
Wait 2
Min
Transport
1 Min
Time
3 1to10
Machine Time 0 Min
A200
Wait
shift
0 Min
3 1to10
Machine Time 0 Min
Wait
shift
0 Min
3 1to10
Machine Time 0 Min
Wait
shift
0 Min
3 1to10
1 at a time
No lot size
1 at a time
1 at a time
1 at a time
1 at a time
Reduce Waiting Time: Reels of the same components
need to be grouped and hanged on the stand by loading
team. Piling up reels in cartons and making operator
searching for it need to be stopped. Reel size need to be
in proportion to number of components per board and
order size. This helps in minimizing reel changes and
thus reduces waiting time.
Fig 4: Internal, Loop

Sub Assembly 1 – Surface Mounting Process
(SMD)
Waiting time across Top and Bottom processing for a
single PCB does vary from 40 to 70 % of the total order
processing time per order. Statistics are given in s
table1.
TakT time analysis for SMD
Table 1: Statistics of SMD
Bot
tom
Top
Tot
al
Setup
Time
(Per
order)
1.47
hours
2.12
hours
Lead
Time
(per
board)
13.49
min
14.50
min
3.59 s
27.99
Waitin
g Time
(across
a day)
#
Oper
ators
#
Shifts
5 hours
3
Opera
tors +
1 QA
3
Fig 5: Takt Time analysis for SMD
Following are the wastes which has significant impact
on the performance of the SMD process
Bottleneck Process : Clearly Reflow inspeciton which
takes 5 minutes per top and bottom is the bottleneck,
whose cycle time is way above the cycle time of rest of
the processes and also way abo ve th takt time. Ways
need ot be identified to reduce or normalize reflow
inspeciton stage to correspond to the Takt time to
manage the current delivery promises to custoemr.
High Waiting Time: Every stage has considerable
waiting time which can be reduced. Pick & Place stage
has the maximum waiting time, the main reason being
component error outing and component reels getting
over. Component reels get over frequently. Entire
process waits for reel re-loading. Searching and loading
a reel takes a lot of time.
Pacemaker Process : A loop is any set of operations
through which there is continuous flow. In this case,
loops would indicate the manufacturing lines comprised
of all of the different processes. The Pacemaker at each
loop is the process which sets the pace for the entire
manufacturing line. The term may be used
interchangeably with the term of a bottleneck; however,
they are not equal. The pacemaker is usually the most
upstream process in a continuous flow loop . The
concept of Takt time should be implemented to control
the process. The pacemaker is mostly useful in
production lines, and manufacturing cells which show
fairly consistent product families.
Unnecessary Motion: Operators walk across the length
of the entire SMD process (~300 meters) multiple times.
During reel changes, operators has to walk across to the
loading table at the beginning of BAY 4, find the reel ,
walk back to the reel to feeder loading reels would be
located at the central loading table,
Over processing: Reflow inspection usually takes 5
minutes for top and 5 minutes for bottom. So a total of
10 minutes per board is taken. The defects identified at
this stage are very les. Since the entire chain is handled
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ISSN (Online): 2347-2820, Volume -1, Issue-2, 2013
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International Journal of Electrical, Electronics and Computer Systems, (IJEECS)
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The first process in the chain of processes in SMD ,
screen printing takes only 41 seconds ot finish a panel .
The pick & place machie also take only less than a
minute to procss a panel, bu the man time required there
to place components manually delay the etnire process.
Because of the man itme, the total cycle time for Pick &
Place process is high near to the Takt time. If this
process can perform with lesser lead time,then even
reflow oven can funtion with better utilization as it can
take nearly 8 to 9 boards at a time . If reflow oven taken
8 boards with a processing time of 7 minutes, then the
cycle time for each board within reflow oven comes
down to below 1 second. So total cycle time up to
reflow inspeciton can be made less than 1 second for
each of the processes , which is a huge increase from
current status.

Rework post reflow is too less ~ 0.25 % and
hardly any rejections. So inspection needs to be
made on sampling basis.

Inspect all of first batch (50) of boards and then
5 boards per batch. Inspection has to be made
online
Waiting time
Set up Time
Maintenance
1.14 m
1.47 h
1 hour
Top
10.24
m
3.12 m
2.12 h
Maintenance
1
VA + NVA
Sub Assembly 2 – Through-Hole Process
Total
163 h
Waiting time in Wave soldering area: This is already
described above. The only way to remove this waiting
time is to utilize the machine in full capacity by
introducing more frames. Operators need to be make
sure that 7 to 8 frames are loaded in the machine
sequentially. Increase number of frames of the fixture
for boards for wave soldering so that machine can be
used for its maximum capacity. Currently the number of
frames varies in the range of 2 to 5 for different versions
of DSM. The machine has the capacity to take 10 frames
at a time. As shown above, machine utilization is way
less than norm.
35.5
3.59
1
Transportation: By introducing supermarkets between
wave soldering and Inspection stages, transportation
between stages can be reduced a lot.
Table 2 Final matrices of current state
Bottom
9.43 m
VA + NVA
Waiting Time in stuffing area: Currently operators
push the board to the next person through a slider.
Productivity of each operator cannot be validated
through this set up. So conveyor belt can be introduced
for stuffing which happens in sequential order between 5
operators. This helps to reduce the productivity issues
per operator.
Analysis of Value added Vs Non value added
activities: For an order size of 1000 PCBs, 500 boards
are processed. Each Panel that is processed has 2 PCBS
in it. Bottom Lead time Total is 9.43min. Top Lead time
Total is 10.24. Pick & Place machine waiting time is 40
to 70 %. Final matrices of the current state are shown in
table 2.
Cycle Time
3.59
Since the board has already soldered with components
by the SMD process, those components need to be
protected from the soldering process. for this purpose,
machine inserted components need to be shielded with
the use of a frame in such a way that only those newly
inserted components would be exposed through the
soldering process. Thus wave soldering is a combination
of manual and machine process. Post soldering and
cooling, the boards need ot be inspected for the newly
inserted components to make sure they are placed at the
correct location, and the soldering is proper etc. Post this
inspection, boards need to be moved to the testing
section. So a final inspection of all the boards, a through
checking based on a checklist is performed to ensure
quality .Any defect found are re-worked and the details
are entered into the computer for logging purpose.
Boards are then temporarily stored for transportation to
another building. This stage comprises of following
sequential steps Stuffing-- > Wave Soldering -- > Post
Wave soldering Inspection  Final Inspection are the
sequence of operations.
Bottleneck Process Analysis – Reflow Inspection: As
evident from figure above, lead time for reflow
inspection is way too above the allowed or desired Takt
Time. So clearly this stage is a bottleneck and the first
place in the value chain where work in progress
inventory is piled up. Since the entire processes before
reflow inspection is done by machines (as per the
modified VSM), the possibility of errors would be
continuous which can be easily identified though
sampling than 100 % inspection. This is also proved by
the following observation.

Set up Time
Unnecessary motion: A method need to be devised
remove unnecessary motion of operators between
beginning and ending of Wave soldering process to
collect the fixtures. This is identified as a waste.
Table 3 shows as is statistics for current state value
stream. The statistics are per order processing time, final
matrices, value added and non-value added activities
Table 3 Final matrices of current state
Cycle Time
Waiting time
163
35.5
VA + NVA
NVA
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International Journal of Electrical, Electronics and Computer Systems, (IJEECS)
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Table 4 Final matrices of current state
Cycle Time
Waiting
time
Set up Time
Maintenance
/down time
Bottom
Top
18 min
6.5 min
20 min
6.5 min
1.08 hours
3 hours
1.08 hours
components takes 2 to 3 min additional whereas same
can be done by machine in no time if sufficient feeder
sticks available. The entire SMD process gets paced
based on this manual intervention and lead time
increases. If this manual intervention can be included in
the machine pick & place process, entire SMD process
can be automated and pacing becomes better.
Total for
500 boards
316.6h
54.16
2.16
3
Ways to make SMD process continuous:

Over Processing: 100 % inspection i.e. inspection of
every single board in every order, takes a lot of time.
But the amounts of defects identified are considerable
and rework is done immediately on the boards.
Considering these facts, it is recommended.

Components that are not coming is reels are
currently being placed manually. It adds to the lead
time. Those components need to be bought in reels
itself .Getting more stick feeders is another option.
Between batches of 50, the board loading is manual
where boards are loaded one by one. This need to
be changed to pre-loading of 50 boards and loading
of the tray to the machine after each batch.
Super Market pull system analysis :
An inventory supermarket (kanban stock point) like a
supermarket is a place where small inventory is
available and one or more downstream customers come
to the supermarket to pick out what they need. The
upstream work center then replenishes stocks as
required. When continuous flow is impractical, and the
upstream process must operate in batch mode, a
supermarket reduces overproduction and limits total
inventory. Supermarket Pull Systems have proven to be
very efficient at eliminating wastes caused by
overproduction. By linking the bulk of the operations to
the customer´s demand, companies have seen a lot of
success. However, pull systems are very difficult to
establish in a high-mix, low-volume environment. The
reason for this is that a very high amount of WIP needs
to be kept in order to have a stock of all of the different
types of product. However, the production mix as the
product goes downstream should be analyzed to see
where it is not very necessary to maintain a lot of WIP.
Fig 6: Takt Time analysis
Bottleneck Process: As clearly seen in the graph above,
lead time of each sub process across top and bottom is
way too above the recommended Takt Time. The main
drawback of this stage is that, it is a totally non
continuous flow with each stage functions independent
of other, though sequential in stages.. Wave soldering
process has the highest lead time and clearly main
bottleneck. Stuffing process is another candidate for
improvement. Since stuffing is completely manual,
there is more room for mishandling and errors as well.
IV. RESULTS

Pace maker Process: Because of the non – continuous
flow of nature, no pacemaker process can be identified
as though-hole sub assembly. Both the inspection stages
are currently carried out 100 %, i.e. for each and every
panel is inspected. Manual logging of details like errors
identified and fixes given etc also need to be carried out.
Since there are few reworks happening at each of the
inspection stages, it is advisable to continue with the
inspection stages. A method study needs to be done on
the process to see what all sub activities can be
automated

Future State VSM Statistics for Sub Assembly 1 –
SMD Process
After the implementation of changes to SMD to remove
the manual intervention, the modified statistics would be
as follows. Man time would be completely removed.
The additional component, with the help of stick feeder
would be inserted by the machine itself. So the total lead
time is reduced from 19.67 to 8.81.Since reflow oven
has the capacity to take up to 10 PCB panels at a time,
as the pick & place machine releases PCBS in a faster
pace, reflow oven would be able to process them in the
same pace. Hence the utilization of reflow oven also
increases. Though it takes 7 minutes ti process one
board, if 4 cards flows through the machine at any
given point of time , its averaged lead time per board
would be less than or equal to 2 min.
Further analysis of the Current State Map
Continuous flow through production line analysis:
In SMD process, between pick & Place and re-flow
oven, the flow becomes non continuous due to the
intervention of operator s. Manual time to place ½
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
process, once that process is levelled out, reflow oven
starts getting frequent boards and its utilization has
increased proportionately.
Reflow inspection, which was considered as a real
bottleneck is handled with the help of sampling
methodology. The latest statistics is given in figure 7.
Major Future State statistics of SMD
Lead time changes would be as given in Table 5 and
improvement matrices for SMD is given in Table 5.
Table 5 Future statistics for SMD
Botto
m
Top
Total
Lead
time(Curren
t State)
9.43 min
Setup
Time(Futur
e State)
4.10 min
Improvemen
t
43%
10.24 min
4.71 min
46%
19.67
8.81
45 %
Ways to reduce set up would be the following.
Introduction of color to the differentiate between reel of
different components, Grouping all the reels of same
components to one tag ,For getting bigger sized reels for
most frequently used components in any given order. I.e.
Instead of giving standard sized reels, Supplier has to be
given bigger sized reels based on the order size to avoid
frequent reel changes and to reduce searching required
form the high number of components with repetition.
Since the components are supplied by AM technologies
itself, and increased demand is their own requirement,
they would be more than ready to help SFO with these
changes. Discussion with SCM team confirmed that, reel
size can be adjusted if already mentioned to the
suppliers or if guidelines can be given to them. Post
these changes are implemented, the improvement
matrices for SMD would be as given in Table 6.
Figure 7: Pacemaker analysis

Following are the recommendations to improve future
state statistics for through-hole process.
Stuffing: Introduction of a conveyor belt for stuffing
process: Conveyor belt would increase the efficiency of
working of the operators who are working in sequence
to fix the components to the PCB. It would enable the
workers to keep a constant pace ot the work and would
not be depend on the pace of individual resources.
Wave Soldering: It is a stage where 8 to 10 fixtures are
introduced to the product. Operator takes 2 minutes to
load a PCB into the fixture and put the frames in the
conveyor of the wave soldering machine. That means
every 2 minutes boards are entering wave soldering
machine. Considering wave soldering machine takes 4
to 5 minutes to process a board. It would be able to
process minimum 2 cards constantly in that interval.
Introduce an automatic trolley system or pushing trolley
system that works between the ending porting and
beginning portion of Wave Soldering machine. : This
would help eliminate unnecessary motion of operators
between the 2 ends of the machine and the waiting time
of the machine until the frames are reached at the
beginning and processing has started.
Table 6 Improvement in matrices for SMD
Bottom
Top
Total

Setup
Time
( Per
order)
Current
State
1.47
hours
Setup
Time
( Per
order)
Future
State
40 min
to 1
hour
2.12
hours
1 to
1.12
hours
3.59
hours
1.6 to
2.12
hours
Changes
40 min –
54.64%
1 hour –
31.97
1 hour –
52.835
1.4 hour
– 33.96
Future State - Sub Assembly 2 – Through Hole
Process
Improvement
31 % to 55 %
34 % To 53 %
Better scheduling of stuffing and wave soldering so as to
avoid the delay caused by different shift timings
between the 2 operations : Currently stuffing team only
works on day shift – i.e. 8 am to 4 pm – shift, where as
both the previous process ie SMD and wave soldering is
/ can be run on all the 3 shifts . Unless cards are made
available for wave soldering post stuffing, it cannot start
the processing. Consider a scenario where SMD has
started on second shift i.e. 4 pm 12 pm. By the time day
shift starts, cards would be ready for stuffing team.
During this entire processing wave soldering machine is
waiting. Once manual stuffing starts processing, cards
gets piled up as wave soldering machine is slow
30% To 55 %
Final result of Pacemaker and Flow changes of
SMD
Pick & Place process was identified as the pacemaker
process. By removing manual intervention, lead time is
reduced as well continuous flow is ensured. This
resulted in considerable lead time reduction in that
process stage alone. Since pick & place is a pacemaker
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compared to the manual stuffing. Better sequencing
between the 3 operations is necessary.

process, once that process is levelled out, reflow oven
starts getting frequent boards and its utilization has
increased proportionately.
Future State Lead Time
Reflow inspection, which was considered as a real
bottleneck is handled with the help of sampling
methodology described in last chapter.
The latest
statistics would be as given in figure 8.
Lead time changes are shown in Table 7. Set up time is
150 minutes per board, which cannot be reduced more
than this. Stuffing needs maximum 50 minutes to load
all components.
Table 7 Lead time improvements for Through-hole
Lead
Lead
time
Time
Improvement
(Current (Future
State)
State)

Bottom
18 min
14 min
22%
Top
20 min
16 min
20%
Total
38
30
21%
Machine Utilization & Waiting Time Results
The 2 proposals to decrease waiting time as well
increase the utilization of Wave soldering machine
considerably are .
Figure 8: Future state Takt Time analysis & Result
V. CONCLUSION
1. Increase in number of frames per product versions of
DSM: Number of frames increased to 10 per product
version from current number of 2 / 4 would considerably
reduce waiting time for the machine. Once the machine
starts processing more frames within the stipulated 4
minutes timeframe, the average processing time per
frame would reduce to as less than 1 minute.
If lead time can be reduced with the introduction of lean
tools and methodologies more PCBs can be produced
with the available machine and resources. Value Stream
mapping tool of Lean is used in this plant to analyze
current production processes in detail for a selected
product family DSM. DSM has 6 versions of products
being produced almost throughout the month, with a
current requirement of 8000 to 10000 pieces per month.
2. Enable automatic or mechanical movement of frames
back to the beginning of the chain than the current
operator lead movement.The time taken to move the
frames back to beginning of the machine workstation
after cooling and removal of board from the frames adds
to the waiting time. It also adds fatigue to the operator to
move between the work stations in frequent duration just
to pass the empty frames.
By identifying waste at SMD, through- hole, testing,
final inspection & packing sub-assemblies, lead time
reduction is made possible. Also by introducing flow
and pacemaker processing through TakT time analysis,
lead times have been levelled across stations.
Considerable improvement in lead time is made possible
across all the three sub-assemblies of DMS production.
Machine utilization has increased. Producing to Takt
time is been made possible across the value chain. This
modified statistics shows that, it is possible to meet the
increased demand of the customer with the available
resources; facilities provided all the suggested changes
are implemented.
With increased number of frames, lot size is also
increased from 2 or 4 to 8 or 10. So the processing time
has reduced to the new processing time + cooling time.
Waiting time improvement is found to be 66 % as given
in table 8.
Table 8: Waiting time improvements for Through-hole
Current State
50 hours

Future State
16.6 hours
Thus Value Stream Mapping is proved to a very
valuable tool for analysis of Current value stream of a
high mix low volume production scenario. Identifying
waste and removing it, implementing flow concept and
Takt time levelling are powerful concepts which are able
to bring phenomenal improvements to current state of
production flow.
Waiting time
reduced to
66%
Final result of Pacemaker and Flow changes
Pick & Place process was identified as the pacemaker
process. By removing manual intervention, lead time is
reduced as well continuous flow is ensured. This
resulted in considerable lead time reduction in that
process stage alone. Since pick & place is a pacemaker
Owing to lack of time, all changes proposed could no be
implemented to observe results and hence possible
output only could be included in this thesis. As an
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International Journal of Electrical, Electronics and Computer Systems, (IJEECS)
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extension of this work, the results can be verified
through simulation.
reduction: an Indian case study. Production
Planning & Control, 2005
REFERENCES
[4]
Hines, P., Rich, N., Bicheno, J., Brunt, D., Taylor,
D., Butterworth, C. & Sullivan, J.. Value stream
management. International Journal of Logistics
Management, 1998
[5]
Tapping , D.,Luyster, T., & Shuker, . T. Value
stream management: Eight steps to planning,
mapping and sustaining lean improvements.
NewYork , NY : Productivity Press, 2002.
[1] Peter Hines, Nick Rich, The seven value stream
mapping tools, Lean Enterprise Research Centre,
Cardiff Business School, Cardiff, UK.
[2]
The basics of Value Stream Mapping, , CMTC California Manufacturing Technology Consulting,
San Fernando Valley Secti, 2003
[3]
Seth, D. & Gupta, Application of value stream
mapping for lean operations and cycle time
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