48 ISE Magazine | www.iise.org/ISEmagazine
In every manufacturing organization, packaging plays a very important role in shipping
products to customers. The main functions of packaging are to prevent damage during
handling, shipment and delivery to the customer. In terms of cost, packaging does not add
value but is an essential part of the process. Packaging design depends on many factors such
as size, weight, how delicate is the product, product features, shelf life, temperature and the
mode of shipment.
This is a case study of packaging materials used for protecting products from damage dur-
ing shipment to end customers and distribution centers. There are several different shapes of
parts molded on special type of molding machines using two chemicals and film roll. The
machines, chemicals and film are all proprietary materials supplied by one company. The
molding machines were purchased some time back and consumable items are bought as
required from the vendor.
The packing materials made by these machines were placed inside corrugated boxes and
sealed at the end of the packing line. The boxes were placed on a wooden pallet and moved
to shipping by a forklift. Twelve different parts were molded on these machines, which
operated 9.5 hours per shift for two shifts, five days a week. The average cycle time for
making a part is about 1.28 minutes. The average efficiency assumed was 90%. The parts
were stored in seven kanban carts designed to hold specic quantities based on average daily
usage by three assembly lines with integrated pack stations and included safety stock for at
least one shift.
Twenty-four rolls of film were consumed in a week making these parts. These lines as-
sembled six different high-dollar volume products that constituted 70% of sales made in
the plant. Maintenance was responsible for start-up and any major issues that affected the
operation of these machines.
There was a small packing line where miscellaneous products were being packed in boxes.
The quantities were not significant, and the line operated in first and second shifts. This line
was close to molding machines. One person was assigned to this line for packing products,
ensuring continuous availability of packing materials used by the three packing lines mak-
ing high value products, checking all carts at the beginning of the shift to see how many had
parts, and speaking to assembly line setup workers to monitor what was planned to be made
on the shift. This person was trained to change molds, load film rolls, do minor trouble-
shooting of machines and ensure all carts and lines were stocked with parts required in the
shift for packing and meeting of production goals.
Issues affecting function of the cell
No study had been done to determine actual capacity of these machines. There were no
good metrics to monitor the installed capacity or use of equipment. Because of variations in
product variety and quantity on a daily basis, it had a ripple effect on molded parts required
for packing.
A case study of packaging line process improvement
Solutions in practice by Raj Sanne
case study
June 2019 | ISE Magazine 49
Some types were found to be inad-
equate and during other times were far
in excess of actual requirements. This
also had impact on storage because
carts were not available. Some carts had
parts that were not required during the
shift, resulting in kanban cart shortages.
There was no system of communica-
tion for the packers to know what was
planned to be assembled in the shift or
the quantity of parts on hand other than
a visual check and discussions with as-
sembly line setup workers. This made
it difficult for any meaningful planning
for the machines to run in a shift. This
was compounded by the responsibility
of a packer having to pack miscellaneous
products and complete shift work.
In the first shift, two technicians
from maintenance helped the packer
start machines, which took about 30
minutes, as well as plan and make parts
for the lines. This was considered to be
nonvalue-added work as the technicians
were also responsible for maintenance
of machines in case of major problems,
along with attending to problems on
the assembly lines. They were doing
part of the work that was supposed to
be done by the person assigned to pack
products. This also had a ripple effect on
other maintenance issues that occurred
in the shift on other assembly lines in
the division.
In the second shift, only one per-
son (the packer) was managing both
the small packing line and five mold-
ing machines. Maintenance was called
in whenever there were issues with the
molding machines. There was no help
from maintenance in the second shift
for the packer.
Project objective. Determining
one person was not able to do all the
assigned work covering packing and
managing the production of parts on
these molding machines created conict
between production and maintenance
over smooth functioning and meeting
daily productivity goals. An impartial
review of the situation was undertaken
to develop solutions that once imple-
mented would improve the functioning
of the whole cell.
Study methodology. The inde-
pendent review project was assigned to
a group of industrial engineers. They
had discussions with supervisors, pack-
ers and managers to understand cur-
rent processes and factors affecting the
smooth functioning of the cell. The
focus of the study was on the use of
molding machines considered impor-
tant in making parts for the assembly
lines. It was decided to observe the op-
eration of these machines and identify
any causes for stoppage covering both
shifts. Studies over an extended period
were done to gather representative and
reliable data for determining the reasons
and understand the issues affecting these
machines. A simple format of data col-
lection sheet is shown in Figure 1.
Capacity utilization. Snapshot of
studies for two weeks to cover both
shifts were done to identify downtime
that had an impact on the capacity and
workload of the packer assigned to man-
age these machines. The average scrap
rate was 5%. As no study had been done
to determine the theoretical capacity, it
was decided to focus on estimating use
of existing machines. The table in Fig-
ure 2 gives details of the calculations.
From the table, assuming the events
are mutually exclusive, it is clear the cu-
mulative probability of uptime for up to
five machines is 62.5% in a shift. From
this, we can infer that in a shift of only
about five hours, four to five machines
were working. This equates to 37.5% of
lost installed capacity. It is clear there is
scope for improving capacity to meet
any additional demand before increas-
ing operating shifts and adding more
machines in the cell. These calculations
FIGURE 1
Setting a template
A simple format is used to create a data collection sheet to troubleshoot problems.
FIGURE 2
Logging the data
The capacity and use of machines are calculated and recorded.
50 ISE Magazine | www.iise.org/ISEmagazine
case study
excluded factors like an ideal run rate
and the scrap generated because of vari-
ous reasons. If these are factored into
calculations, the actual uptime will be
less than 62.5%. Some major reasons
contributing to downtime identified
during the study are discussed in the
following sections and in Figure 3.
Mold. Because of the process, the
lm sometimes was getting clogged
inside the mold, resulting in bad parts
and stoppage of the machine. Stop-
ping the machine and cleaning inside
the mold occurred about 22% of the
time in a shift.
Film. During the process of making
parts, the film sometimes would jam
between rollers, leading to stoppage,
which required opening the rollers to
clear the jam and resume operation.
This happened about 11% of the time
in a shift.
Pile up near machine. There was
no good system for collecting parts
coming out of the mold. They were
thrown out from the mold and fell
on the floor near the machine. As
the pile built up near the machine, it
sometimes obstructed the closing of
the mold door, leading to stoppage.
Parts lying on the floor were picked
and later arranged in carts about 22%
of the time in a shift.
Machine problems. Sometimes the
machines had problems, leading to
stoppages that required review by the
maintenance team about 11% of the
time in a shift.
By addressing the above major list of
action items, it is possible to improve
the available capacity from 60% to
about 77.6% without incurring any ad-
ditional cost.
Floor space: In the area where the
machines were located, space was lim-
ited and it was difficult to bring in carts
to park in the area. A rack was in the
middle in front of machines, hinder-
ing free movement and storage of carts.
Also, space was required for two carts
on which molds were kept at point-
of-use (POU) close to machines. Rolls
with 24 to a pallet were not close to
POU. On average, each machine re-
quired one roll per day. Assuming 80%
of available free space, the estimated
number of empty carts for molded parts
that could be parked in front of ma-
chines was 30. A sketch of the layout is
shown in Figure 4.
Suggested improvements
Film. It was decided to add storage
space to the existing mold storage carts
for keeping three rolls of film on each
cart at POU. That would ensure all ma-
terials required for molding parts are at
POU near machines.
Floor space. In the existing ar-
rangement, there was a rack on which
packing materials were kept that was
acting as a monument in the middle of
the cell. The sketch of the proposed lay-
out is shown in Figure 5. It was decided
to free up space in front of the machines
by removing the rack in the center. This
added 15% more free space for keeping
the carts and arranging parts near the
machines. It would enable five more
empty carts to be parked in the area.
FIGURE 3
Finding the causes
Several major reasons contributing to downtime were identified during the study.
FIGURE 4
Previous floor space
The existing layout of the mold machines, where space was limited.
June 2019 | ISE Magazine 51
Labor. Based on discussions, it was
decided to first implement the sug-
gested changes before determining a
need for a dedicated resource. Based
on the outcome of improvements after
about a month, it was decided to review
and make a decision on having a dedi-
cated resource only for doing all tasks
covering inventory management, load-
ing molds and making parts and minor
troubleshooting to ensure that parts
required for both shifts are available as
required. This person was expected to
be given additional work of packing
products and concentrate only on mak-
ing pack materials.
Standard work and training. It
was decided to standardize and docu-
ment the entire process to ensure the
consistency of work in the cell. It was
also decided to invite the equipment
supplier to train maintenance and op-
erational technicians on the machines.
Implementation plan
A meeting was held with the manager
and supervisors to discuss the recom-
mendations and develop an implemen-
tation schedule. It was agreed to first
implement the layout change as part of
the improvement process. Based on dis-
cussions, a matrix of action items, start
and end dates and responsibility was
developed for implementing the layout
change. The details of action items are
seen in Figure 6.
It was decided to monitor improve-
ments and make necessary changes as
required for a period of one month.
Based on the workload, the need for
a dedicated resource would be deter-
mined at a later date.
The study illustrates how simple ap-
proaches to problem-solving using ap-
propriate tools can lead to substantial
improvements at low cost and have a big
impact on productivity. It is clear that
before any investment decisions to aug-
ment capacity are made, it is necessary
to determine the current use of exist-
ing equipment. By addressing the causes
and reducing downtime to improve
utilization, it is possible to add capac-
ity without adding to costs and meet the
actual requirements of assembly lines.
This is an example of the Toyota
Production System on the need for
continuous focus and problem-solving
to maintain stable production. It is wise
to addresslow-hanging fruit” issues
rst and resolve them before addressing
bigger issues. By not addressing such
issues, any major improvements made
are suboptimal and will not yield full
benefits.
Raj Sanne is an industrial engineer with
more than 10 years of experience in manu-
facturing and operational improvements in
different sectors. He has worked as an in-
dustrial and mechanical
engineer in aerospace and
automotive companies. He
spent more than 15 years
consulting on productivity
improvements in businesses
in India. He has bachelors
degrees in math, physics,
chemistry and industrial en-
gineering from universities in
India, and is working on his
MBA.
FIGURE 5
Creating more room
The proposed layout of the mold machine area frees up space.
FIGURE 6
Action items
Steps toward improvement on the package line.