productivity improvement in an aluminium die casting unit by applying lean principles
TRANSCRIPT
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Chapter 1
INTRODUCTION
1.2 Lean Manufacturing
Lean manufacturing or lean production, often simply "lean", is a systemic method for
the elimination of waste ("Muda") within a manufacturing process. Lean also takes into account
waste created through overburden ("Muri") and waste created through unevenness in workloads
("Mura"). Working from the perspective of the client who consumes a product or service, "value"
is any action or process that a customer would be willing to pay for.
Essentially, lean is cantered on making obvious what adds value by reducing everything
else. Lean manufacturing is a management philosophy derived mostly from the Toyota
Production System (TPS) and identified as "lean" only in the 1990s. TPS is renowned for its
focus on reduction of the original Toyota seven wastes to improve overall customer value, but
there are varying perspectives on how this is best achieved. The steady growth of Toyota, from
a small company to the world's largest automaker, has focused attention on how it has achieved
this success.
1.3 Project Overview
The project is being carried out in DIMO CASTINGS Pvt. Ltd.
1.3.1 Aim
To increase productivity in internal logistics at bay -2 of the organization by reducing work
in progress inventory , optimum utilization of space and improving ergonomic factors for fettling
operation.
1.3.2 Objectives
-decentralizing the fettling process
-to create an optimum layout design for fettling operations
-reduce flow process time
-re-evaluate material handling techniques by considering work study and ergonomics principles
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
1.3.3 Methodology
The crux of the project was to implement lean principles and techniques. To have lean
principles and techniques implemented, a study on the current scenario in the plant was made.
The various methodologies adopted to implement lean principles included the use of flow
process charts, spaghetti diagrams and understanding concepts like FTE, work cell concept and
ergonomics. Material flow was to be studied using spaghetti and the over utilized and under-
utilised resources in terms of men and space were to be highlighted using the FTE concept and
studying the path travelled by men and materials respectively. Also, to analyse time, a time study
analysis flow process charts were to be used. Adopting cell manufacturing by designing work
cell concept was necessary and a suitable fixture for gear cases which takes in consideration
human ease of working, safety and time reduction was to be designed .
1.3.4 Benefits of the project
-reduction in manufacturing lead time
-optimum utilization of space, manpower and machines
-reduction in material travel time
-reduction in work-in-progress inventory.
1.3.5 Objectives achieved
The project was carried for a period of three months (Jan 2015 - Mar 2015). The system was
studied in detail and after frequent interactions with officials the major issues were realized. The
major concerns were poor material flow for fettling operations, excessive work-in-progress
inventory, poorly designed work stations,non-value adding movement of men and material.
The issues were studied in detail and necessary data for the same were collected from
officials in the organization. Data interpretation and analysis were carried out. With the help of
the officials some suggestions were implemented.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
The objectives and their corresponding results are as follows:
1. Decentralizing the fettling process
Fettling operations were carried away from respective machines, this scenario proved very
inefficient henceforth a new layout for fettling operations were proposed near the respective
machines.
2. To create an optimum layout design for fettling operations
A detailed work-cell concept was developed which:
reduced the existing number of operators
utilizes optimum
reduced non value adding transportation
reduced WIP inventory
3. Reduce flow process time
The proposed designs were analysed using flow process charts and as a function of
quantity*frequency*distance. The proposed methods proved improved values theoretically
4. To re-evaluate material handling techniques by considering work study and ergonomics
principles
The current material handling methods for gear case were not ergonomically efficient and had
poor considerations for the operator’s safety. Taking into consideration all these factors, a fixture
which incorporated two steps of operations into one was designed.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Chapter-2
THEORETICAL BACKGROUND AND LITERATURE REVIEW
2.1 History of Lean Manufacturing
Henry Ford was one of the first people to develop the ideas behind Lean Manufacturing.
He used the idea of "continuous flow" on the assembly line for his Model T automobile, where
he kept production standards extremely tight, so each stage of the process fitted together with
each other stage, perfectly. This resulted in little waste.
But Ford's process wasn't flexible. His assembly lines produced the same thing, again
and again, and the process didn't easily allow for any modifications or changes to the end product
– a Model T assembly line produced only the Model T. It was also a "push" process, where Ford
set the level of production, instead of a "pull" process led by consumer demand. This led to large
inventories of unsold automobiles, ultimately resulting in lots of wasted money.
Other manufacturers began to use Ford's ideas, but many realized that the inflexibility of
his system was a problem. Taiichi Ohno of Toyota then developed the Toyota Production System
(TPS), which used Just In Time manufacturing methods to increase efficiency. As Womack
reported in his book, Toyota used this process successfully and, as a result, eventually emerged
as one the most profitable manufacturing companies in the world.
2.2 Lean Wastes
Fig 2.1 Lean Wastes
2.2.1 Overproduction
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
It is unnecessary to produce more than the customer demands, or producing it too early before it
is needed. This increases the risk of obsolescence and the risk of producing the wrong thing. It
tends to lead to excessive lead and storage times. In addition, it leads to excessive
work-in-process stocks which result in the physical dislocation of operations with consequent
poorer communication.
2.2.2 Defects
In addition to physical defects which directly add to the costs of goods sold, this may include
errors in paperwork, late delivery, production according to incorrect specifications, use of too
much raw materials or generation of unnecessary scrap . When defect occurs, rework may be
required otherwise the product will be scrapped.
Generation of defects will not only waste material and labor resources, but it will also create
material shortages, hinder meeting schedules, create idle time at subsequent workstations and
extend the manufacturing lead time.
2.2.3 Inventory
It means having unnecessarily high levels of raw materials,works-in-process and finished
products. Extra inventory leads to higher inventory financing costs, higher storage costs and
higher defect rates.It tends to increase lead time, prevents rapid identification of problems and
increase space requirements. In order to conduct effective purchasing, it is especially necessary
to eliminate inventory due to incorrect lead times.
2.2.4 Transportation
It includes any movement of materials that does not add any value to the product, such as moving
materials between workstations. Transportation between processing stages results in prolonging
production cycle times, the inefficient use of labour and space. Any movement in the firms could
be viewed as waste. Double handling and excessive movements are likely to cause damage and
deterioration with the distance of communication between processes.
2.2.5 Waiting
It is idle time for workers or machines due to bottlenecks or inefficient production flow on the
factory floor. It includes small delays between processing of units.When time is being used
ineffectively, then the waste of waiting occurs. This waste occurs whenever goods are not
moving or being worked on. This waste affects both goods and workers, each spending time
waiting. Waiting time for workers may be used for training or maintenance activities and should
not result in overproduction.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
2.2.6 Motion
It includes any unnecessary physical motions or walking by workers which divert them from
actual processing work. This might include walking around the factory floor to look for a tool,
or even unnecessary or difficult physical movements, due to poorly designed ergonomics, which
slow down the workers. It involves poor ergonomics of production, where operators have to
stretch, bend and pick up when such actions could be avoided.
2.2.7 Over-processing
It is unintentionally doing more processing work than the customer requires in terms of product
quality or features such as polishing or applying finishing in some areas of product that will not
be seen by the customer. Over-processing occurs in situations where overly complex solutions
are found to simple procedures. The over-complexity discourages ownership and encourages
employees to overproduce to recover the large investment in the complex machines.
2.2.8 Under-utilized and over utilized factors
It includes machines, labours ,excessive maintenance procedures that consume way more time
and money but in return do not add any substantiate values. Every factor in the system should
be utilized in an optimum fashion.
2.3. Lean Tools
2.3.1. 5S
Eliminates waste that results from a poorly organizedwork area (e.g. wasting time looking
for a tool).
Organize the work area:
- Sort (eliminate that which is not needed)
- Set In Order (organize remaining items)
- Shine (clean and inspect work area)
- Standardize (write standards for above)
- Sustain (regularly apply the standards)
2.3.2 Andon
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Visual feedback system for the plant floor that indicates production status, alerts when
assistance is needed, and empowers operators to stop the production process. Acts as a real-time
communication tool for the plant floor that brings immediate attention to problems as they occur
– so they can be instantly addressed.
2.3.3 Bottleneck Analysis
Identify which part of the manufacturing process limits the overall throughput and
improve the performance of that part of the process. Improves throughput by strengthening the
weakest link in the manufacturing process.
2.3.4 Continuous Flow
Manufacturing where work-in-process smoothly flows through production with minimal
(or no) buffers between steps of the manufacturing process. Eliminates many forms of waste
(e.g. inventory, waiting time, and transport).
2.3.5 Gemba (The Real Place)
A philosophy that reminds us to get out of our offices and spend time on the plant floor
– the place where real action occurs. Promotes a deep and thorough understanding of real world
manufacturing issues – by first-hand observation and by talking with plant floor employees.
2.3.6 Heijunka (Level Scheduling)
A form of production scheduling that purposely manufactures in much smaller batches
by sequencing (mixing) product variants within the same process. Reduces lead times (since
each product or variant is manufactured more frequently) and inventory (since batches are
smaller).
2.3.7 Hoshin Kanri (Policy Deployment)
Align the goals of the company (Strategy), with the plans of middle management (Tactics)
and the work performed on the plant floor (Action). Ensures that progress towards strategic goals
is consistent and thorough – eliminating the waste that comes from poor communication and
inconsistent direction.
2.3.8 Jidoka (Autonomation)
Design equipment to partially automate the manufacturing process (partial automation is
typically much less expensive than full automation) and to automatically stop when defects are
detected. After Jidoka, workers can frequently monitor multiple stations (reducing labor costs)
and many quality issues can be detected immediately (improving quality).
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
2.3.9 Just-In-Time (JIT)
Pull parts through production based on customer demand instead of pushing parts through
production based on projected demand. Relies on many lean tools, such as Continuous Flow,
Heijunka, Kanban, Standardized Work and Takt Time. Highly effective in reducing inventory
levels. Improves cash flow and reduces space requirements.
2.3.10 Kaizen (Continuous Improvement)
A strategy where employees work together proactively to achieve regular, incremental
improvements in the manufacturing process. Combines the collective talents of a company to
create an engine for continually eliminating waste from manufacturing processes.
2.3.11 Kanban (Pull System)
A method of regulating the flow of goods both within the factory and with outside
suppliers and customers. Based on automatic replenishment through signal cards that indicate
when more goods are needed. Eliminates waste from inventory and overproduction. Can
eliminate the need for physical inventories (instead relying on signal cards to indicate when more
goods need to be ordered).
2.3.12 KPI (Key Performance Indicator)
Metrics designed to track and encourage progress towards critical goals of the organization.
Strongly promoted KPIs can be extremely powerful drivers of behavior – so it is important to
carefully select KPIs that will drive desired behavior.
The best manufacturing KPIs:
-are aligned with top-level strategic goals (thus helping to achieve those goals)
-are effective at exposing and quantifying waste (OEE is a good example)
-are readily influenced by plant floor employees (so they can drive results)
2.3.13 Muda (Waste)
Anything in the manufacturing process that does not add value from the customer’s
perspective. Eliminating muda (waste) is the primary focus of lean manufacturing.
2.3.14 Overall Equipment Effectiveness (OEE)
Framework for measuring productivity loss for a given manufacturing process.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Three categories of loss are tracked:
a) Availability (e.g. down time)
b) Performance (e.g. slow cycles)
c) Quality (e.g. rejects)
Provides a benchmark/baseline and a means to track progress in eliminating waste from a
manufacturing process. 100% OEE means perfect production (manufacturing only good parts,
as fast as possible, with no down time).
2.3.15 Poka-Yoke (Error Proofing)
Design error detection and prevention into production processes with the goal of achieving
zero defects. It is difficult (and expensive) to find all defects through inspection, and correcting
defects typically gets significantly more expensive at each stage of production.
2.3.16 Root Cause Analysis
A problem solving methodology that focuses on resolving the underlying problem instead
of applying quick fixes that only treat immediate symptoms of the problem. A common approach
is to ask why five times – each time moving a step closer to discovering the true underlying
problem. Helps to ensure that a problem is truly eliminated by applying corrective action to the
“root cause” of the problem.
2.3.17 Standardized Work
Documented procedures for manufacturing that capture best practices (including the time
to complete each task). Must be “living” documentation that is easy to change. Eliminates waste
by consistently applying best practices. Forms a baseline for future improvement activities.
2.3.18 Takt Time
The pace of production (e.g. manufacturing one piece every 34 seconds) that aligns
production with customer demand. Calculated as
Planned Production Time / Customer Demand.
Provides a simple, consistent and intuitive method of pacing production. Is easily extended to
provide an efficiency goal for the plant floor (Actual Pieces / Target Pieces).
2.3.19 Total Productive Maintenance (TPM)
A holistic approach to maintenance that focuses on proactive and preventative
maintenance to maximize the operational time of equipment. TPM blurs the distinction between
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
maintenance and production by placing a strong emphasis on empowering operators to help
maintain their equipment. Creates a shared responsibility for equipment that encourages greater
involvement by plant floor workers. In the right environment this can be very effective in
improving productivity (increasing up time, reducing cycle times, and eliminating defects).
2.3.20 Value Stream Mapping
A tool used to visually map the flow of production. Shows the current and future state of
processes in a way that highlights opportunities for improvement. Exposes waste in the current
processes and provides a roadmap for improvement through the future state.
2.3.21 Visual Factory
Visual indicators, displays and controls used throughout manufacturing plants to improve
communication of information. Makes the state and condition of manufacturing processes easily
accessible and very clear – to everyone.
2.4 Takt time and Full Time Equivalent
2.4.1 Takt time
The expression of takt time is derived from the German word “Takt” for the pace of a piece
of music. In Operations Management, the takt time is defined as the maximum time it can take
to produce a unit in order to keep up with demand. If, for example, the demand is at 6 units per
minute, the takt time would be at 10 seconds per unit.
Once the takt time has been determined, the target manpower can be calculated as the ratio
of total labor content(the time sum of all worksteps needed to produce one flow unit) and takt
time. The target manpower is the number of employees (or other resources) needed to operate
the process at takt time if the work could be divided evenly between them Since this is an
idealized calculation, the outcome will most likely not correspond exactly with reality, one
reason being that it is not always possible to evenly split work between employees if different
skills are needed. Still, calculating the target manpower provides a good starting point for line
balancing.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Line balancing is the process of dividing an existing workload as evenly as possible between all
of the available resources in order to increase overall productivity. If, for example, one
workstation has a lot of idle time, maybe it can take over some of the workload from the
workstation at the bottleneck. The basic line balancing procedure consists of four steps:
(1)Calculate the takt time
(2) Assign tasks in a way that keeps all processing times below the takt time
(3) Make sure that all tasks are assigned
(4) Minimize the number of workers needed
The general ability of an organisation to adjust its capacity and scale it up and down in order to
adjust to changes in demand (the so-called staffing to demand) is an important form of flexibility,
which can be achieved e.g. with temp workers or overtime work. A special form of line balancing
is the so-called dynamic line balancing, which includes walking around the workstations during
production, looking for pileups and rearranging resources in order to keep up with demand.
Cycle time, labor content and idle time are indicators for assessing the productivity of a process.
Cycle time: The cycle time is defined as the time between the output of two successive flow
units (e.g. the time between two served customers or two treated patients). It is always equivalent
to the time of the longest process step.
Total labor content: The total labor content is defined as the time sum of all process steps. If,
for example, a process consists of two steps each claiming 20 seconds, the total labor content is
40 seconds.
Idle time: The idle time is defined as cycle time minus processing time. The idle time thus tells
us for how long a resource (e.g. a worker) is not able to do anything, because he has to wait for
another resource. If, for example, one worker in a sandwich restaurant prepares sandwiches
while another operates the register, the second worker has to wait for a sandwich to be finished
in order to collect on the customer.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
2.4.2 Full Time Equivalent
The ratio of the total number of paid hours during a period (part time, full time, contracted)
by the number of working hours in that period Mondays through Fridays.
The ratio units are FTE units or equivalent employees working full-time. In other words,
one FTE is equivalent to one employee working full-time.
For example: You have three employees and they work 50 hours, 40 hours, and 10 hours
per week – totalling 100 hours. Assuming a full-time employee works 40 hours per week, your
full time equivalent calculation is 100 hours divided by 40 hours, or 2.5 FTE.
2.5 Line Balancing
Line Balancing is leveling of the workload across all operations in a line to remove
bottlenecks and excess capacity.
When you consider mass production, components are produced or operations on that
component are carried out in lines on set of machines instead of single machine. A line may be
assembly line, modular line or section, a line set with online finishing and packing. A line
includes multiple work stations with varied work contents. Production per hour is varied
depending on work content (standard minutes of particular task/operation), allocation of total
manpower to a particular operation, operator skill level and machine capacity. Operation with
lowest production per hour is called as bottleneck operation for the line.
A bottleneck operation in a line determines the output of the line. That is why it is very
important to increase production of the bottleneck processes or operation.
Line supervisors, work study officers find ways to increase production from the
bottleneck operation and implement those means one by one to level work across operations. In
layman language this is called as line balancing.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Secondly Line balancing is essential because, if excess capacity of work is burdened on
operators the under utilized cost for other operators adds to the producton cost there by
decreasing profitability.At the time of machine/manpower planning based on work content of
each operations, they prepare a sheet where operation wise manpower is calculated. Most of the
cases calculated manpower gives fraction of figure but in real you can’t allocate to fraction of
manpower to an operation. So manpower planner decides to which operations one machinist, to
which operations two machinist or where only single machinist will be allocated for two or three
operations. Planner makes this decision based on calculated data.
3.1 COMPANY BACKGROUND
DIMO Castings Pvt. Ltd. has carved a niche in the precision pressure die casting industry by
manufacturing high quality products that cater to the Automobile, Electronics and Engineering
and Healthcare sectors.
Established in the year 1965 in Bangalore by late Mr. Pathmanabhan , DIMO Castings applies
modern innovative processes and develops in-house expertise to manufacture precision pressure
die casting components to meet the highly exacting requirements of the clients. DIMO Castings
has witnessed a tremendous growth since its inception. Currently, there are two manufacturing
units: one in Bangalore , Karnataka and the second in Hosur, Tamil Nadu.
As the requirement of the customer has changed from casting procurement to finished parts
supply, TURN TECH- a sister concern has been established to support the machining
requirements.
3.2. QUALITY CONFORMANCE
Precision and quality are not just terms of DIMO Castings. They are synonymous with the
organization. The processed and techniques that have gone into manufacturing the products to
the highest quality standards are reflected in the certification and award and bestowed on DIMO
Casting.
The quality control measures with PPAP, KAIZEN and 5 S Housekeeping activity have enabled
DIMO Castings to adhere to JIT practices for timely delivery of high quality products to the
customers. The products manufactured by DIMO Castings are of such high quality and precision
that even clients recognise with Demings Award accept our self-certified products, which are
then taken to the production line directly
3.3. CERTIFICATION AND AWARDS
DIMO Castings in an ISO 9001: 2008 Company certified by TUV NORD. The organization is
bestowed with the best foundry Award (Nationwide) from Alucast India for two consecutive
years- 2001, 2002
3.4. COMPANY’S VISION AND MISSION
3.4.1 VISION
To serve the society by manufacturing and supplying world class products that provide high
value for money
3.4.2 MISSION
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
To enhance the quality of life of all our customers, business associates, supplier partners, stake
holders, end-users and our internal team, by being obsessive about product quality and customer
delight.
3.5. COMPANY CORE VALUES
3.5.1 ADAPTABLITY
The ability to be flexible and adaptable to client’s requirements and priorities.
3.5.2 TECHNICAL EXPERTISE
Adopting the state-of-the-art-technology and combine it with the expertise of the in-house team
for best results.
3.5.3 COMMITED WORK FORCE
A strong and experienced team who strive to make the company’s name synonymous with
excellence.
3.5.4 CUSTOMER FOCUS
Committed to continuous improvement in quality, processes and systems, thereby delighting the
customers.
3.6. COMPANY LOCATION
PLANT STATE LOCATION
1 KARNATAKA Bommasandra, Bangalore
2 TAMIL NADU Hosur
3.7. ORGANIZATION STRUCTURE
The company has successfully grown to its current state of grandeur because of its highly
dedicated staff.
Sl. No DEPARTMENT No of staff
1 ADMIN 1
2 HR 1
3 FINANCE 4
4 PURCHASE 1
5 QUALITY CONTROL 12
6 INSPECTION 20
7 MAINTENANCE 5
8 DIE MAINTENANCE 8
9 HOUSE KEEPING 7
10 STORE 7
11 PRODUCTION 94
12 DISPATCH 2
13 TRANSPORT 5
14 FURNACE 12
15 FETTLING 82
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
16 CNC 27
TOTAL 288
3.8 CUSTOMERS
CUSTOMER PROFILE
TVS Motors
company ltd.
Tyco Electronics,
Portland
Kirloskar Toyota
Textile Machinery
Miscellaneous
requirements
Country India
USA &China India India
Profit share 60%
15% 20% 5%
Product description 20gms to 2kgs of
automobile parts
200gms to 500gms
of medical
equipment
600gms of gear
transmission
housing
300gms
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
3.9 PRODUCT LINE
DIMO Castings manufactures a wide range of product of which few are as show below
1. ENGINE PARTS
Crank cases Small engine components
Cylinder block Cylinder head
2. GEAR PARTS
Gear case Auto gear transmission housing
3. OIL FLTERS AND
COVERS
Oil pump cover Cap oil filters
4. CLUTCH
ASSEMBLIES
Housing clutch Clutch covers
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Clutch assembly
5. BELT DRIVES AND
WHEEL ASSEMBLY
Footrest brackets Wheel hub
Brake panels Belt drives
6. ELECTRICAL
ELECTRONIC AND
MEDICAL EQUIPMENTS
Motor covers Medical Equipment
Electronic assemblies
Chapter - 4
SYSTEM STUDY
4.1 System Analysis
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
DIMO Castings Pvt. Ltd is a leading manufacturer of aluminium castings located in
Bommasandra, Bangalore. The company has clients from automobile, textile, healthcare and
various other industrial sectors. Our project was carried out at bay-2 of the organization to
improve material flow for fettling operation and to reduce the manpower for optimum output.
The plant operates two 12-hour shifts for production and two 8-hour shifts for fettling operations.
4.2 Process Flow
The raw material used for the process is aluminium ingots. The aluminium ingots are
melted in the mother furnace; the mother furnaces are maintained at a temperature of about
1200˚c.
The molten metal undergoes a process called degassing usually necessary to reduce the
amount of hydrogen in the solution formed due to chemical reaction with atmospheric water
vapour which further leads to porosity. The molten metal is then carried to respective holding
furnaces near the respective casting machines. The holding furnaces are maintained at a
temperature of 600°C so as to maintain its molten state. The furnaces, both mother and holding
furnace are refilled in order to maintain temperature.
The molten metal is then poured by an operator into the die casting machine. The
automatic machines are equipped with a robotic arm which does the same. The machines based
on their specification produce the respective products. Heavy components are produced on
machines with higher force applying capacity and vice versa.
The cast piece is removed by the operator using industrial tongs for manual machines
and robotics arms for automatic machines. It is left to cool for a while. The casting is inspected
for defects and stored in a pallet. The runner for light weight castings are removed near the
machine by hammering the runner from the casting and for heavy components a band saw is
used. The runner is re-melted in the holding furnace.
The castings are then transported in the pallets using cranes to the fettling area where
necessary finishing processes like burr removal, grinding and drilling are carried out. The
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
finishing processes for components with high tolerances are machined using CNC machines and
the other components are fettled manually. The final products are subjected to inspection; critical
components are subjected to 100% inspection while others are inspected by sampling. The
rejcted pieces are re melted in the mother furnace.
Fig 4.3 Process flow
4.2.1 ALUMINIUM INGOTS
Aluminium ingots is the raw material used in DIMO. These Aluminium ingots are provided by
their respective customers. Each ingot is estimated to weigh around 6kgs.
4.2.2 CLEANING AND DEGASSING
Degasification is the removal of dissolved gases from liquids, especially water or aqueous
solutions. Degassing of molten Aluminium alloys is a foundry operation aimed to
Aluminium ingots
Loading in melting furnace
Molten metal
cleaning and degassing
Transfering to holding
furnace
Metal pouring
Casting production
Fettling and
trimming
Shot blasting and powder
coating
Inspection packaging
and despatch
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
remove Hydrogen dissolved in the melt There are numerous possible methods for such removal
of gases from solids.
Methods:
Pressure reduction
Heating
Membrane degasification
Substitution by inert gas
Addition of reductant
5.2.3 FURNACE:
A furnace is a device used for high-temperature heating.
Furnaces are broadly classified into two types
Combustion Furnace
Electric Furnace
Combustion Furnace
Combustion Furnaces are the furnaces which uses fuel as the source of heat to melt the materials.
Electric Furnace
Electric furnace is heating chamber with electricity as the heat source for achieving very high
temperatures to melt alloy metals. The electricity has no electrochemical effect on the metal but
simply heats it.
4.2.4 CASTING
Die casting is a metal casting process that is characterized by forcing molten metal under high
pressure into a mold cavity. The mold cavity is created using two hardened tool steel dies which
have been machined into shape and work similarly to an injection mold during the process. Most
die castings are made from non-ferrous metals,
specifically zinc, copper, aluminium, magnesium, lead, pewter and tin based alloys. Depending
on the type of metal being cast, a hot- or cold-chamber machine is used.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Hot-chamber die casting
Hot-chamber die casting, also known as gooseneck machines, rely upon a pool of molten metal
to feed the die. At the beginning of the cycle the piston of the machine is retracted, which allows
the molten metal to fill the "gooseneck". The pneumatic or hydraulic powered piston then forces
this metal out of the gooseneck into the die. The advantages of this system include fast cycle
times (approximately 15 cycles a minute) and the convenience of melting the metal in the casting
machine. The disadvantages of this system are that it is limited to use with low-melting
point metals and that aluminium cannot be used because it picks up some of the iron while in the
molten pool. Therefore, hot-chamber machines are primarily used with zinc, tin, and lead based
alloys.
Cold-chamber die casting
These are used when the casting alloy cannot be used in hot-chamber machines; these include
aluminium, zinc alloys with a large composition of aluminium, magnesium and copper. The
process for these machines start with melting the metal in a separate furnace. Then a precise
amount of molten metal is transported to the cold-chamber machine where it is fed into an
unheated shot chamber (or injection cylinder). This shot is then driven into the die by a hydraulic
or mechanical piston. The biggest disadvantage of this system is the slower cycle time due to the
need to transfer the molten metal from the furnace to the cold-chamber machine.
4.2.5 FETTLING
The complete process of cleaning of castings is called fettling. It involves the removal of the
cores, gates, sprues, runners, risers and chipping of any of unnecessary projections on the surface
of the castings.
The fettling operation are
1. Removal of gates and risers
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
2. Removal of fins and unwanted projections
1. Removal of gates and risers- Gates and risers can be removed from casting by several methods
depending upon size and metal used.
Hammer-They can be broken by hitting with the hammer.
Cutting saw-These saws may be hand saw and power saw. Mostly the hand saws
are used for small and medium but power saw are used for large work.
Flame cutting-This type of method is specially used for ferrous materials of large
sized castings where the risers and gates are very heavy.
2. Removal of fins, rough spots and unwanted projections.
The casting surface after removal of the gates may still contain some rough surfaces left at the
time of removal of gates and these are removed with the help of grinding machines and hand
files.
4.2.6 SHOT BLASTING
Shot blasting is a method used to clean, strengthen (peen) or polish metal. There are two
technologies used: wheel blasting or air blasting.
Wheel blasting- directly converts electric motor energy into kinetic abrasive energy by rotating
a turbine wheel. With these large amounts of accelerated abrasive, wheel blast machines are used
where big parts or large areas of parts have to be derusted, descaled, deburred, desanded or
cleaned in some form.
Air blast- machines can take the form of a blast room or a blast cabinet, the blast media is
pneumatically accelerated by compressed air and projected by nozzles onto the component. For
special applications a media-water mix can be used, this is called wet blasting.
4.2.7 POWDER COATING
Powder coating is a type of coating that is applied as a free-flowing, dry powder. The main
difference between a conventional liquid paint and a powder coating is that the powder coating
does not require a solvent to keep the binder and filler parts in a liquid suspension form. The
coating is typically applied electrostatically and is then cured under heat to allow it to flow and
form a "skin". The powder may be a thermoplastic or a thermoset polymer. It is usually used to
create a hard finish that is tougher than conventional paint.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
INSPECTION
Inspection is an organized examination or formal evaluation exercise. Inspection involves
measurements, tests and gauges applied to certain characteristics in regard to an activity. The
inspections carried out in DIMO are visual inspection and inspection using pneumatic gauges.
Chapter - 5
DATA COLLECTION AND ANALYSIS
The main aim of data collection is to understand the current level of performance of the
production line. Data was collected after thorough investigation and understanding of the various
processes,limitaions and records. Takt time, FTE(full time equivalent) operators, material
movement as a function of F*Q*D(frequency*quantity*distance) were determined and a suitable
workcell design was proposed.
5.1 Data collection
5.1.1 Voice of customer
- Improve fettling layout at bay-2 of the plant.
- Substantiate with solid values to show current and proposed methods
- Design a highly functional work-cell concept incorporating efficient
material handling and ergonomic factors.
5.1.2 Key issues
- organization meets daily demand but fails to achieve in-house efficiency.
- no structured and standardized workflow i.e various departments do not work
in synchronous manner.
- poor production planning.
- labour issues
- failure to analyse the root cause and purpose of various operations.
- excessive material handling.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
- excessive work in progress inventory.
- poor ergonomics in work areas for various operation.
Fig5.1 Fish bone diagram
5.1.3 Translating to measurable paramaeters:
Layout design - as a function of quantity*frequency*distance
Data collection - FPC( Flow process charts)
Proper utilization of labour - FTE (Full Time Equivalent Calculations)
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
5.1.4 Data collection objectives:
The below mentioned objectives are in a sequential manner of achieving the various goals.
1) Build a layout design from scratch; both a virtual as well as 3 dimensional models of the
layout to its approximate scale.
2) Understand the flow of material flow using flow process charts (bay -2 only)
3) Collect demand details for the month of February 2015 for the selected product (gearcase) in
order to calculate respective takt time of the product.
The limited time and scope of the project could focus only on a single product. The product
for the study was thus selected from the despatch details as on February 2015.
Table 5.1 Despatch details
Component Despatch FEB 2015
GEAR CASE 39300
CYLINDER BLOCK 40350
RCS SMALL 8300
DRUM REAR EXCEL 16750
MOVABLE DRIVE JUPITER 39200
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Fig 5.1 Histogram representing demand of product
Among the above gearcase, cylinder block and movable drive Jupiter were of high demand and
these products tend to have a constant demand throughout the year.
Among the three gearcase was thus selected as the subject of study.
The components in bay -2 were studied in detail and a clear picture about the material
handling system was obtained. The overview study was carried out using flow process chart and
graphically representing them on a scaled virtual layout as shown below as spaghetti diagram.
This provided insights into under-utilized space in bay-2. The study further helped us understand
the root cause for the faulty material handling systems.
0
10000
20000
30000
40000
50000
DESPATCH FEB 2015
HOUSING CLUTCH APACHE 14295
COVER BREATHER 28620
CYL HEAD 26450
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
I & M
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RECEIVING SHIPMENT
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FETTLING AREA
FURNACE
FURNACE
FURNACE
STORES
STORESC
NC
STORES
STORES
DIE COAT TANK
PALLET PALLET PALLET
S
O
S
PA
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INSPECTION
DESPATCH
PALLET
PA
LLET
Fig 5.2 Plantlayout(Spaghettidiagram)
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Fig 5.3 Gearcase
The project focusses on machine ck200d which mainly produces gearcase and oil cap for
KTTM .The current process utilizes 1 operator for removing the runner as the component comes
out of the machine, unloaded automatically. The component is then stored near the machine in
pallets. The pallets occupy an approximate area of 1m*1m, the no. of pallets near machine with
WIP stock varies based on demand and availability of labourers for successive operations. The
pallets are then carried to bay-1 for grinding. There are 2 grinding machines with 2 wheels on
opposite sides which can be operated by 2 operators per machine, there is WIP before the
grinding operation. The component is again piled for the next operation leading to WIP
inventory. The component then undergoes removal of cap by an operator and further leads to
WIP inventory. It then undergoes minor fettling operations by an operator and again proceeds to
unnecessary WIP. The component then moves towards the drilling machine in bay-1 for further
operations, there is unnecessary piling before and after drilling. The component is then moved
for final marking and inspection by another operator.
The component in total utilizes 5 operators and 2 helpers for moving the component
around The total area covered by WIP 5m*5m and finished goods 2m*2m.
The above mentioned study about the material flow was studied using flow process charts
over a period of 4 weeks and an average values of the various operations are mentioned in
sequence in the below provided flow processs chart.
Table 5.2 Detailed process map (Flow process chart)
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
FLOW PROCESS CHART TYPE : MAN / MATERIAL / MACHINE
CHART NO : SHEET NO : OF : SUMMARY
SUBJECT CHARTED: ACTIVITY PRESENT PROPOSED SAVING
GEAR CASE N15 OPERATION 7
TRANSPORT 7
DELAY 5
INSPECTION 1
STORAGE 1
DISTANCE (m) :
LOCATION : T IME (man-hr):
OPERATIVE(S): CLOCK NO COST :
CHARTED BY : DATE: LABOUR:
MATERIAL:
APPROVED BY : DATE: TOTAL :
SL NO DESCRIPTION QTY. DIST TIME SYMBOL REMARKS
(m) (min)
1 Casting(Bay-2) 100 73 *2 Piled in Pallet near m/c 100 *3 Removal of Runner(Minor) 100 5 *4 Temporarily stored(Pallet) 100 *5 Transported to Grinding Area(Bay-1) 100 61 3 *6 Grinding Edges(B-1) 100 7 *7 Piled on Floor(B-1) 100 *8 Fettled(B-1) 100 20 *9 Piled on Floor(B-1) 100 *
10 Loaded to Pallet 100 0.5 *11 Transported to Drilling Area(BAY-1) 100 13 3 *12 Loaded to Crate 100 0.5 *13 Drilled (2 m/c s) 100 *14 Loaded to Crate 100 0.5 *15 Transported to BAY-2 100 80 *16 Piled on Floor 100 *17 Marked 100 *18 Inspection 100 *19 Loaded to Dispatch Pallet 100 1 *20 Transported to dispatch area 100 5 *
21 Storage 100 4 *
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Fig 5.3 Pie Chart representing value added and non-value added activities
The only value adding factor among the above mentioned steps is operation and it amounts to
only 33% of the overall steps and non-value adding constituted the remaining 77% which
includes transportation, delay, inspection, storage. The project aimed at reducing the non-value
adding activities and thereby increasing the value adding factors to improve efficiency of work
in the current system.
5.2 ANALYSIS
This phase focusses on working on the acquired data and helps in understanding the
setbacks in the current system.
5.2.1 Analysis objectives:
1) Plot under-utilized and over utilized areas in the plant using spaghetti diagram.
2) Deduce relevant parameters such as frequency, quantity, and distance travelled from the FPCs
5) Efficient utilization of labour
33%
33%
24%
5%5%
VALUE ADDED AND NON VALUE ADDED
OPERATIONS TRANSPORTATIONS DELAY INSPECTIONS STORAGE
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
5.2.2 Stepwise analysis:
The aim of constructing spaghetti diagram was to understand if the material flow was
happening in an efficient manner, i.e if the internal logistics factors were optimally utilized. The
results proved otherwise. The spaghetti diagram clearly shows that fettling operations for various
products were not streamlined. There are two options to improve this scenario
Streamline the fettling operation at the fettling area itself for all the components.
Construct a workcell design to incorporate respective fettling operations besides
the machines itself.
Among the two when compared in general by considering respective value added and non-value
added activities the latter proved highly efficient. Another reason for the conclusion was the
optimum utilization of space criteria.
The material flow in the organization was studied for all machines in bay-2 . this provided us
insight into the utilization of space in the plant. The reasons for such poor utilization were
analysed and among them the following proved critical.
- sticking to existing or previous patterns of material flow.
- adamant to change at various levels of management.
- improper planning, analysis and evaluation while constructing a layout.
Fig 5.4 Under-utilized areas in bay-2
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
The system of study was CK 200d( component - Gearcase n15). The material was studied
from flow process charts and analysed as a function of frequency, quantity and distance. The
above mentioned parameters were analysed for a 12 hour shift and the following data was
collected over period of 4 weeks.
Frequency refers to the number of times the component has been moved between respective
departments in a shift. Quantity refers to the number of components moved for every single
movement between respective departments. Distance refers to the distance moved for every
single frequency. The parameters are considered as a product function as the cost associated with
same would be a multiple of these factors ,hence the product function helps us to compare the
corresponding improvements using the same function.
Table 5.3 Material Travel data as a function of Frequency*Quantity*Distance
FROM–TO DEPARTMENTS
PRESENT
(FREQUENCY*QUANTITY*DISTANCE)
CASTING - GRINDING
(2*500*63)=63000
GRINDING - DRILLING
(10*100*15)=15000
DRILLING – CAP REMOVAL
(10*100*15)=15000
CAP REMOVAL –
INSPECTION
(10*100*60)=60000
INSPECTION – PACKAGING
(1000*1*2)=2000
PACKAGING - DESPATCH
(2*500*1)=1000
TOTAL
∑ (F*Q*D)=156000
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
The time taken for various critical operations were analysed. Takt time for the component
was calculated using despatch details of February.
Inorder to efficiently utilize various operations and labour effort has to be equally distributed
among the respective operations in an optimally designed sequence.
Table5.4 Line Balancing based on Takt time
GEAR CASE N15 COMPONENTS
PER hr
TIME FOR 1
COMPONENT IN
seconds
Line balancing (equal division
of time)
seconds
CYCLE TIME
(MC)
82 44 44
GRINDING 450 8 4.25
DRILLING 720 5 4.25
CAP REMOVAL 1200 3 4.25
INSPECTION
AND MARKING
1200 3 4.25
Total 63
takt time = 61 sec
The takt time was calculated and in order to efficiently utilize the time for various operations
the machining time was reduced from the takt time as changing the machine time proved to be
a concept out of scope of the project, the remaining time was equally divided among the
remaining crucial operations and the following conclusions were made.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Fig 5.5 Histogram representing Line Balanced Time
From the above graph it is clear that operations 2 and 3 take time above the takt time whereas
operations 4 and 5 take much lesser than takt time. Therefore it can be concluded that operations
3,4 and 5 are not adding any substantial value to the product and those operations can be
combined for proper utilization of labour. Furthermore these operators could be assigned other
jobs.
The table below shows the necessary time for each operator by combining the operations.
The scenario has proved that from having two operations working below takt time , the system
has reduced it to a single operation and savings in terms of the operators salary in the long run
Table 5.5 Line balanced time by combining operations
OPERATIONS TIME FOR 1 COMPONENT
IN sec
Line balancing
(equal division of time)
CYCLE TIME (MC) 44 44
GRINDING 8 8.5
DRILLING,CAP REMOVAL AND
INSPECTION
11 8.5
44
8
5 3 3
44
4.2
5
4.2
5
4.2
5
4.2
5
C Y C L E T I M E ( M C )
G R I N D I N G D R I L L I N G C A P R E M O V A L I N S P E C T I O N A N D M A R K I N G
TIM
E (S
ECO
ND
S)
LINE BALANCED BASED ON TAKT TIME
TIME FOR 1 COMPONENT IN sec Line balancing (equal division of time)
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Fig5.6 Histogram representing Line Balanced time for combined operations
The calculations provided cannot justify the problem completely as the effort put in might
vary for operations but equal distribution of effort is very essential to achieve a profitable
scenario. The following analysis further proves this statement.
Inorder to analyse efficient utilization of manpower full time equivalent (FTE) operator
calculations were carried out. The methodology was crucial for analysis as the previous method
does not take into consideration the demand details for the product. It refers to the time allotted
to a worker such that he is occupied full time. The calculation provides us the number of workers
required for the given operation time so that they are occupied full time when the shift I running.
The number of operators are calculated based on the takt time (production details February
2015)
FTE = (Total time for all operation on a component+ clearance time)
Takt time
The value obtained as FTE indicates “number of operators” required such that their occupied.
0
5
10
15
20
25
30
35
40
45
50
CYCLE TIME (MC) GRINDING DRILLING,CAP REMOVAL ANDINSPECTION
TIM
E (S
ECO
ND
S)
Line balance based on Takt time(Combined operations)
TIME FOR 1 COMPONENT IN sec Line balancing (equal division of time)
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Table 5.6 Full time equivalent calculataions
Time(seconds)
Machine 44
Grinding 8
Drilling 5
Cap removal 3
Inspection and marking 3
Total 63
ideal
Production feb 39300
per day 1403.571429 1404
per hour 58.5 59
Time for 1 component(seconds) 61.01694915 61
No. of operators (61+10)/62 1.032258 2
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
From the above calculations it was evident that 2 operators are sufficient to carry out the
works currently being carried out by 5 operators. The system was studied with various
combinations of operation sequences. The inherent constraints were analysed and the following
optimum sequence for operation were suggested.
Table 5.7 Sequence of operations and time taken for respective operation
OPERATIONS MACHINE OPERATOR-1 OPERATOR-2
MACHINE 44 sec
RUNNER REMOVAL 3 sec
GRINDING 8 sec
DRILLING,CAP REMOVAL 5 sec
FINAL INSPECTION,
MARKING AND DESPATCH
3 sec
The plant currently has only a single shift for fettling while production happens 24 hours, this
leads to WIP inventory at the beginning of the day. The proposed system would ideally eliminate
the duration taken in fettling the previous night’s production.
In order to provide a larger picture, gantt charts were constructed . It was inferred from the gantt
chart that operator 1 can complete 5 components and operator 2 can complete 4 components for
the time taken for a single casting. The set of operations( i.e Operator-2 = 5,3;Operator-1=8,3)
for each operator clearly explains the rate at which components finish their operations from the
respective operators.
This can only be achieved by improving current layout and by proper scheduling. The explained
scenario is possible in ideal scenarios but if adopted thoroughly the system would show
comparative improvements even considering some clearances and tolerances.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Fig 5.7 Gantt load chart representing operation sequence time
5.2.3 WORKCELL DESIGN
44
3 8
5 3
3 8
5 3
3 8
5 3 5 3 5 3
3 8
M A C H I N E
O P E R A T O R - 1
O P E R A T O R - 2
TIME (SECONDS)
GANTT CHART
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
This design focusses on improving the existing processes by incorporating necessary
changes and then study their effects. If the effects are positive then maintain the system or else
try different alternatives are tried.
From the above data calculations it is evident that high number of workers are being
utilized ineffectively, the optimum number of workers for the machine ck200d was estimated to
be 2. Hence a suitable work cell design was proposed.
The design objectives:
- less material travel
- less man travel
- ergonomic workspace
- combine multiple functionalities wherever possible
- flexible to incorporate further improvements
- Operator-1 - Operator-2
Fig 5.8 Work-cell design
5.2.4 WORKCELL DESIGN EXPLAINED
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
The work cell constitutes of 2 workers as mentioned. The above figure clearly shows the
positions of the respective operators.
The process begins with operator -1.He removes the casting from the bin or chute as the
machine has automatic unloading facility. He then places it in the pallet. The process repeats for
20 components. Approximate cooling time was observed to be 20 minutes. The operator then
removes the 21st component and places in the pallet and takes the 1st component he had placed
in the pallet. This is done as 20 minutes buffer time was allowed for natural cooling.
The operator- 1 takes the first component and does the grinding operation. The operator then
pushes the component onto the next table with a rubber stopper to prevent the component from
falling down. The operator -1 repeats the above mentioned procedure.
The operator - 2 takes the component from the table and loads it onto a specially designed
fixture to suffice drilling and cap removal using a pneumatic hand drill.
5.2.5 Reasons for using the fixture:
-The current system utilizes vertical drilling machines for this operation. The component does
not need such excessively powered equipment, as the end objective is to only remove the
covering of holes in the casting due to die design.
-Vertical drilling machine has its own challenges like occupies excessive space, not portable and
uses more power.
-Current system does not have any holding system. The operation is carried out by holding the
component with hand which is against the principles of ergonomics.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Fig 5.8 Fixture design
Fig 5.9 Gearcase
The component is slotted in the fixture and holes are aligned with the respective holes of the
component. The hand drilling machine is then channelled through the respective holes, the
pneumatic hammering function is used to remove the cap.
The operator then proceeds for final inspection, marking and despatch.
The improvement in the system flow can be understood by comparison of the present and
proposed by considering the (quantityfrequency*distance) function and flow process chart.
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
5.3 IMPROVEMENT ANALYSIS
The proposed workcell design showed improvement by reducing
- number of operations from 7 to 4, savings 3 steps from the previous system
-number of transportation steps from 8 to 4
-number of delay steps from 6 to 1
-distance travelled from 166 metres to 22 metres
-operators from 5 to 2
Table 5.8 Proposed workcell design Flow process chart
The improvement can be understood clearly from the histogram below. The project
objective of reducing non value adding factors and thereby increasing value addition in the
various aspects of production is clearly understood through the pie chart below
FLOW PROCESS CHART TYPE : MAN / MATERIAL / MACHINE
CHART NO : SHEET NO : OF : SUMMARY
SUBJECT CHARTED: ACTIVITY PRESENT PROPOSED SAVING
GEAR CASE PROPOSED OPERATION 7 4 3
TRANSPORT 8 4 4
DELAY 6 1 5
INSPECTION 1 1 0
STORAGE 1 1 0
DISTANCE (m) : 166 22 144
LOCATION : TIME (man-hr):(min)
OPERATIVE(S): CLOCK NO COST :
CHARTED BY : DATE: LABOUR: 5 2 3
MATERIAL:
APPROVED BY : DATE: TOTAL :
SL NO DESCRIPTION QTY. DIST TIME SYMBOL REMARKS
(m) (min)
1 Casted 100 105 *
2 Removal of runner 100 5 *
3 Loaded to pallet 100 0.025 5 *
4 Stored in pallet near machine 100 * 20 components are stored for cool off time
5 Unloaded for grinding 100 0.025 5 *
6 Grinding operation 100 14 *
7 Pushed near drilling machine 100 2 4 *
8 Drilling,cap removal ,inspection 100 17 *
9 Loaded to pallet 100 0.025 4 *
10 Transported to despatch area 100 20 3
11 Storage 100 *
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
Fig 5.10 Histogram comparing present and proposed scenarios
Fig 4.11 Pie chart for proposed material handling system
The improvement is clear from the existing process in terms of percentage it can be clearly
stated that there is an improvement of about 4% and crucial decrease in the non value adding
parameter ( transportation) from 24% to 9%
4 4
1 1 1
7 7
5
1 1
CHANGE IN PRESENT & PROPOSED METHODS
PROPOSED PRESENT
37%
36%
9%
9%
9%
PROPOSED VALUE ADDED AND NON VALUE ADDED
OPERATIONS TRANSPORTATIONS DELAY INSPECTIONS STORAGE
Lean Project to improve material handling system in an aluminium die casting unit
Department of IEM, Bangalore Institute of Technology
The proposed workcell concept was further analysed and improvement from existing
state was prevalent. Similar Frequency*Quantity*Distance analysis were carried out between
respective departments and the following factors were noticed
- frequency and quantity are inversely proportional factors.
-distance was the factor that caused a huge variation in the quantity*function*distnce product
function between previous and proposed workcell design.
Table 5.9 Comparison of present and proposed Frequency*Quantity*Distance
FROM–TO DEPARTMENTS
PRESENT
(FREQ*QUANTITY
*DISTANCE)
PROPOSED
(FREQ*QUANTITY
*DISTANCE)
CASTING - GRINDING (2*500*63)=63000
(1000*1*3)=3000
GRINDING - DRILLING (10*100*15)=15000 (1000*1*2)=2000
DRILLING – CAP REMOVAL (10*100*15)=15000 (1000*1*0)=0
CAP REMOVAL – INSPECTION (10*100*60)=60000 (1000*1*0)=0
INSPECTION – PACKAGING (1000*1*2)=2000 (1000*1*2)=2000
PACKAGING -
DESPATCH
(2*500*1)=1000 (2*500*20)=2000
TOTAL ∑ (F*Q*D)=156000 ∑ (F*Q*D)=9000
SAVINGS 156000 - 9000 = 147000
The system contributes to a saving of about 1,47,000 units . This unit will be a multiple factor
for cost and hence can be help in understanding the improvement in terms of percentage.
The system adopts ideal scenarios hence the value can only be considered as a factor for
theoretical studies. In terms of percentage the system shows an improvement of about 94%.