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Table 2 - Results of the Experi-ment Characteristics Transhipment Output Time required (c)
experimental campaign: location Pipeline
(a) number; (b) at the end 1 Feeder vessels (a) Tsypnavolok length (b) 10,357.07
of the run (i.e. after 9,552 2 Tsypnavolok 490.04 8,797.16
hours) in nautical miles; (c) 3 5 Tsypnavolok 550.00 8,591.65
to complete the pipeline, in 4 6 Belushya 550.00 10,061.47
hours 5 7 Belushya 526.30 9,545.25
6 7 Belushya 550.00 9,374.39
8 550.00
9
feeder vessel performs a there-and-back servi- 398 days (corresponding to 9,552 hours), i.e. the
ce between the pipe-lay vessel and an on-shore operating time fence allotted to the oil and gas
transshipment point where the mother vessel company to complete the pipeline. Table 2 sum-
downloads the pipes and the feeder vessels marizes the output in terms of pipeline length at
upload the pipes to be carried to the pipe-lay the end of the simulation run and of the hours
vessel. required to complete the pipeline under each run
The location of the on-shore transshipment point of the experimental campaign.
is another decisional variable. The on-shore Six feeders are needed to lay all the pipes under
transshipment point can be selected between Tsypnavolok and eight under Belushya. Moreo-
two alternatives: ver, simulation allows for performing sensitivity
• the port of Tsypnavolok in the Rybachy Pe- analyses to test the robustness of the solutions
against environmental sources of variance (e.g.
ninsula, hereinafter named as Tsypnavolok; weather conditions, traffic along the river chan-
• the port of Belushya in the southwest of the nel, failures) or changes in the topology of the
system. Exactly in this feature lies the great
Southern Island of the Novaya Zemlya arctic advantage of simulation. As a matter of fact, the-
archipelago, hereinafter named as Belushya se sensitivity analyses are not possible (or, at le-
(see again figure 2). ast, very difficult to be performed) by using static
decision support tools based on spreadsheets.
The mother vessel performs a there-and-back
service between either transshipment point and Lean, Six Sigma and
the port of Arkhangelsk, on the Northern Dvina statistical process control
River near its outlet into the White Sea, in the far
north of European Russia. The mother vessel ro- Six Sigma is a methodology developed by Moto-
ute to Tsypnavolok from the port of Arkhangelsk rola in mid 80s, aiming at improving the capability
is composed of two stretches: of industrial processes by addressing and redu-
• a 18.6 nautical miles length river channel, cing sources of variability. The underlying goal of
Six Sigma is to reach a maximum of 3.4 defects
which is a two-way channel going from the per million opportunities. In the 90s, under the
port to the Dvina outlet; no bridge crosses enlightened guide of Jack Welch, General Elec-
the channel and the maximum speed allo- tric successfully employed Six Sigma to improve a
wed in the channel is 3.5 knots; huge number of transactional processes, thus de-
• a 494 nautical miles length open sea stretch. monstrating the applicability beyond manufacturing
processes. Today Six Sigma is applied in a number
The mother vessel route to Belushya from the port of non-repetitive contexts.
of Arkhangelsk is composed of two stretches: An “evolution” of Six Sigma is the so-called Lean
• the above-mentioned river channel; Six Sigma, where the statistical approach of Mo-
• a 605 nautical miles length open sea stretch. torola is merged with the more visual “Lean Thin-
king” approach inspired by the Toyota Production
A simulation model able to represent the system System, resulting in an extremely powerful conti-
described above has been built by means of the nuous-improvement methodology.
ArenaTM simulation software package and an in- Another “well-established” tool that can be suc-
depth experimental campaign has been executed cessfully applied in the ETO Supply Chain are Con-
on it. The decision variables of the experimental trol Charts, which were developed by Walter A.
campaign are the number of feeder vessels and Shewart in the 20’s as a graphical mean to make
the location of the transshipment point. sure that repetitive manufacturing processes were
The length of the simulation run has been set to
20 Impiantistica Italiana - Maggio-Giugno 2015
