In this context, the operators pick the required parts as indicated
on a picking list. They use a cart to collect the parts and to move
inside the supermarket warehouse. They collect the components
without considering their dimensions and weight, just following
the picking list. Moreover, also in this case, the storage allocation
is random, so the operators are forced to travel all the aisles of
the warehouse to collect the necessary items. Another important
aspect is that there is not accurate and real-time updated warehouse
management software due to respectively: presence of wide
locations, of about 3 meters, and not unique link between one item
to one location, but each part can be stocked in different locations,
increasing the complexity of execution of picking.
Then, the long parts (more than 3 m long) can be stocked in vertical
or horizontal way depending by a previous evaluation made
by the operations managers, based on kind of part without considering
time and ergonomics impacts. On the other hand, the small
parts present a great variety of SKUs, mainly based on type of supplier,
but also for this kind of part the dimensions and positions of
SKU are just defined by the supplier without considerations about
the successive picking activities.
After collecting all the parts included in the picking list, the
operators carry the cart to a specific zone. If some parts are not
found, the incomplete cart is put in another defined zone waiting
to be completed.
Starting from this situation, the scope of the project has been
the re-design of the area and especially the definition of new management
of parts and their packages for picking.
Also in this case study, the use of the developed integrated system
has permitted to highlight where to work in a more accurate
manner, optimizing jointly productivity and ergonomics.
In detail, a general full-body analysis based on OWAS method
has been carried out initially for all general picking activities and
then more accurately for only long and small parts.
Moreover, the movements of hip are collected and analyzed in
order to estimate the total travel distance and the number of lowering.
The hand positions investigation completes the global application
of the system to this real case.
From the use of the integrated system, some relevant problems
to be eliminated or reduced have been defined, in order to increase
the productivity considering also the ergonomics aspects.
From the general analysis, one of the most critical aspects is the
difficulty to find the parts due to random and not fixed parts allocation
that involve in high travelled distance and not optimal picking
from an ergonomic point of view.
Consequently, in the new alternatives of supermarket warehouses,
some improvements regard the introduction of fixed allocations
with unique link to the stocked part, and the adoption of class
based storage in order to stock the more requested parts in the most
accessible locations, and finally for some item a new optimal
dimension of SKUs has been defined. All these actions have permitted
to reduce the time to pick and to increase the ergonomics.
In detail, from the analysis of picking of long parts, a critical
comparison has been carried out between the collection of long
parts stocked in vertical and horizontal way. In this case the vertical
stocking system is preferable for the more requested items and
especially for the heavier parts. About the picking of horizontal
pieces, a visual feedback has been given to the operators in order
to show them the best ergonomic modality to perform that activity.
On the other hand, about the picking of small parts, the application
of the developed system has shown the difficulty to find small
parts in wide locations and in some cases the difficulty to pick the
items due to their packages, not optimized for the picking.
In this case, for the more requested items a special zone has
been created where an operator creates the small parts kits
required by the pickers. This area and the workplace, where the
operators prepare the kits, have been optimized based on time and ergonomic point of view, using also a visual feedback for the
operators to demonstrate the most correct management of parts
in that zone.