Warehouse Workflow and Cross-Docking: Design and Operational Analysis

This assignment delves into the analysis of workflow and cross-docking operations within a warehouse setting. It begins by examining the bucket brigade technique, calculating production rates based on worker sequencing (slowest to fastest and fastest to slowest) and determining the fraction of each order produced by each worker. The assignment then explores order pick density and its impact on productivity, discussing different order pick codes and the influence of factors like travel time and SKU integration. Furthermore, the paper examines the efficiency of I-shaped versus L-shaped dock designs, highlighting the advantages of the I-shape in terms of cross-docking operations. Finally, it addresses common problems associated with forklift trucks and dragline systems, including issues related to metal cord integrity, hoist alignment, wheel abrasion, electrification structures, and hook integrity, thereby offering a comprehensive overview of warehouse operations and material handling challenges.

Work Flow And Cross-Docking
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Q 11.6;
i) Production rate in sequencing workers from slowest to fastest;
Bucket brigade is a technique of arranging workers on a flow line, where fewer workers
exist than stations (Bartholdi & Eisenstein, A Self-organising order-picking sysytem for a
warehouse, 1996). The use of bucket brigades exist in two (in its least) mercantile domains:
apparel manufacturing and distribution warehousing (Bartholdi & Eisenstein, A Self-organising
order-picking sysytem for a warehouse, 1996). These domains incorporate 2- and 3-worker
teams apparently. Some of the important properties of this model include; simple for analysis
and natural generalizations inherent behavior. The individual worker order per hour includes;
Worker A=12 min per order
(1/12)*60=5 orders/hour
Worker B=10 min per order
(1/10)*60=6 orders/hour
Worker C=5 min per order
(1/5)*60=12 orders/hour
Since for any bucket brigade line maneuvers of the workers voluntarily intersect to a
fixed point merging to a consummately-balanced line and prime production for 3-worker lines, it
is adequate for the last worker to be fastest for the convergency to a set point (which is holds not
for lines of greater than three workers, since exemplars to the contrary are straightforwardly
found). Nevertheless, where workers scheduled from the slowest-to-fastest, a relevant sense
remains strictly preferable (Bartholdi & Eisenstein, A Self-organising order-picking sysytem for
a warehouse, 1996). The appraisal of stability (one subtracted to the coefficient of the massive
eigenvalue of the set point) becomes adamantly greater when r3 > r2 > r1 than anyplace on the
sub-region with stability. Thus implying, upon the sequencing of workers are sequenced in the
sequence slowest-to-fastest, the structure can oppose disturbances of vast magnitude without
altering the qualitative performance.
Thus, the production rate of this line, determined in orders/hour where the workers are
sequenced from the slowest to the fastest is as calculated below;
∑i=1n i

Where; WorkerA=5 orders/hour
WorkerB=6 orders/hour
WorkerC=12 orders/hour
= (5+6+12) orders/hour
=23 orders/hour
ii) Fraction of each order produced by each worker;
In such an example for three workers, all these 3-worker lines can be established on the
comparative velocities of the workers. Assigning ri = vi/v3 as the correlation of the rate of work
done of the ith worker to that of the rate of third worker, any set of the three workers on this
bucket brigade technique flow line will match to the point (r1,r2) within a drawn figure of the
possible asymptotic behavior of a 3-worker bucket brigade production line (Bartholdi &
Eisenstein, A production line balancing itself, 1996). Thus, the fraction of each order produced
by each worker is calculated as; ri= i/3
Where;
rworkerA =12/5
=2.4
rworkerB =6/5
=1.2
rworkerC =5/5
=1
iii) Production rate when workers are sequenced from fastest to slowest;
When workers are cycled on any other sequence than from slowest-to-fastest, then the
faster gravitates to cope up with and will be hindered by slower ones.
When the subsequent worker is faster than the initial and tertiary workers together, finally
the worker will repeatedly be dragged by the tertiary worker. Thus, the locations of the
employees after walk-backs finally shift betwixt (0,r1/(r1 + r3),1) and (0,0,r1=(r1+r3)), with
subprime production rate of 2(v1+v3) on a drawn figure of the possible asymptotic performance
of a 3-worker bucket brigade production line (Bartholdi & Eisenstein, A Self-organising order-
picking sysytem for a warehouse, 1996). Similarly, when the two initial workers are both rapid
than the tertiary, both are ultimately and repeatedly dragged by he thus the locations of the

employees after walk-backs finally shift betwixt (0,1,1), (0,0,1), and (0,0,0) while the production
rate subsides to 3v3, such that everybnody is reduced to the velocity of the slowest employee.
Thus, the production rate when the workers were sequenced from fastest to slowest is calculated
using the production rate; 3v3
Where; v3 = 5
= 3(5) orders/hour
= 15 orders/hour
Q 11.10; Order pick density;
A distribution centre quintessentially is composed of a store area (or go down) and an
order actualization centre (orders picking forward site). Amid the settlements associated to the
order actualization centre, one of the most remarkable from the service and expense perspective
is the blueprint of the order pick system. (Frazelle, 2002). This additionally influence the service
quality since definite blueprints are more prone to mispicks and office mistakes than more. There
exists the major three order pick codes which include, discontinous order picking (where a
worker collects all the products for a single order on each tour), batch picking (where a worker
picks products for various orders on each trip) and zone picking (where individual worker is
designated to a given space of the godown and sections of the orders allocated to suitable zones)
(Tompkins, White, Bozer, & Tanchoco, Facilities Planning, 2003).
Higher pick density equates higher pick productivity. This is effected by designs of order
pick systems that exhibit multiplex set of settlements which integrate predominantly through
turnout (what number of pickings per hour will be necessitated?), space exploitation (what
number of products must be stowed in a given space?) and expense (what are the fixed and
unfixed expenses?). Integration of numerous SKUs in the similar bin position decreases picking
efficiency where time and motion studies can be done to confirm the specific time penalty
connected to mixing numerous SKUs into the similar bin position. Increase of travel time
develops low order picking productivity which relates to the essence for the use batch and cluster
order picking approach in warehouses so as to reduce this effect. Also, absence of floor level
traditional order picking diminishes productivity which consequently lowers the order picking
output.

Q 13.6; Efficiency of I-shaped compared to L-shaped design docking for alike number of doors;
Among the four paramount roles of warehousing (order picking, receiving, shipping and
storage), the first and the last are quintessentially the vast exorbitant where storage is due to
stock holding expenses, and order picking due to the intensive effort required. Crossdocking as a
logistics system, removes the storage and order-picking roles of a go down and still serve for
receiving and shipping roles. Inside the market dispensation and LTL (less-than-truckload
transportation) lattice cross-docks differ significantly in size/shape. The designs incorporating
shapes of a L, T, or I are vastly apparent and yet the uncommon ones may do also exist, inclusive
of those exhibiting the shape of a E, U, or H.
The I design in more advocated and incorporated due to some fundamental facts inherent
of its design (Frazelle, 2002). First, the small, over-the-dock advance is relevant since cross-
docking actions are effort rigorous, and most of varying labor costs (both direct and indirect) are
assigned to movements betwixt doors. Correspondingly, smaller in size crossdocks exhibit I-
shaped since this blueprint provides the possibility to pass deliveries straight over the dock from
the collecting to shipping door. Secondly, the distances betwixt the afar doors elevates linearly
with the amount number of doors; and thus, the traffic in front of the intermedial doors elevates
as the square of the number of doors.
Accordingly, either through time or the design stage, an I-shaped dock becomes less
efficient as it expands.
Q 13.6; Problems forklift truck and dragline running counterclockwise crossdock experience;
A terminal exhibits diverse material handling methods that are used for convey of
delivery. Forklifts and pallet jacks convey heavy or colossal commodities, while carts convey
relatively smaller commodities. Furthermore, Sizable terminals exhibit draglines, which
disseminates carts about the perimeter of the dock. Some of the common problems associated
with these large material handling machines (forklift and counterclockwise dragline crossdock)
include;
i. Injury or abasement to the metal cord; bird caging, dissolution and wearing are
among the few of the difficulties that can affect metal cord on an forklift truck or a

dragline crane. Some of the common metal cord difficulties include; metal rope
jumping out of the reeving structure, depletion of cord diameter beneath titular (loss
of central support, internal or external dissolution, wear of outside cords), smashed or
threadbare outside cords, abraded or smashed cords at terminal connections and/or
extreme kinking, squashing or fragmenting. The pre-eminent procedure to inhibit
injury or collapse is inspection of the cord wires oftentimes.
ii. Hoist aslant and conjunction concerns; an aloft hoist out of conjunction and aslant in
its movements down the channel can result outstanding stresses and injuries to the
whole hoist structure. The definite indicators of hoist aslant and inadequate
conjunction in its movements down the channel. When in operation, the following
concerns need to be considered; loud rasping noises, fragmented or denture wheel
labium, unusual abrading on the wheels and wheel bearings, additional power
necessitated in moving the hoist through given locations of the channel and/or wheels
that suspend or ascend over the rail and eventually strike down. The difficulty with a
hoist that tracks not rigidly is that over time, intensities not adjudged for in the
blueprint and installation of the aloft hoist results to stresses to the channel supports
and too to the tie-backs or structure supports. These types of stresses can result in:
mishaps, hoist failure, impedimenta downtime and loss on efficiency of productivity
that includes expensive reconstructions and renewal of parts.
iii. Immoderate rasp to hoist wheels; end truck hoops are constituents of aloft hoists that
require oft maintenance, renewals, or confinements. Throughout the life of a hoist’s,
the hoops eventually abrade down due to common utilization of the hoist and will
require to be renewed. Hoops are made from a variety of componets, including
polyurethane for base hoists, amalgams, or small/medium in carbon steel. The greater
the amounts of carbon in the steel, the solid the hoops will be.
iv. Issues with the electrification structures; there exists a good number of diverse
concerns interconnected to an aloft hoist’s electrification structures which may
demand utility or succeeding perpetuation. These include difficulties with contact
interference, difficulties with push stud and/or puffed circuit breaker.
v. Twisted or injured hooks; a hook is delineated to clench a load in a certain and exact
focus. When the load’s weight cannot be reinforced as preconceived by the hook, this

alters the internal probity of the hook and thus alleviate the possibilities of it twisting,
extending, or fissuring. This can definitely lead to a slip off of the load when the hook
extends out the throat aperture.

REFERENCES
Bartholdi, J. J., & Eisenstein, D. D. (1996). A production line that balances itself. Operations Research, 1-
8.
Bartholdi, J. J., & Eisenstein, D. D. (1996). A Self-organising order-picking sysytem for a warehouse.
Bucket brigades.
Frazelle, E. H. (2002). World-Class Warehousing and Material Handling. New York: McGraw Hill.
Tompkins, J. A., White, J. A., Bozer, Y. A., & Tanchoco, J. M. (2003). Facilities Planning. New York: Wiley.
Tompkins, J. A., White, J. A., Bozer, Y. A., & Tanchoco, J. M. (2003). Facilities Planning. New York: Wiley.