NewRail Simulation Modelling for Analysing Rail Freight Operations Dr Marin Marinov Clare Woroniuk September 2012.

NewRail

Simulation Modelling for Analysing Rail Freight Operations

Dr Marin Marinov Clare Woroniuk

September 2012

Outline

• Systems Approach;• Decomposition Approach;• Analytical Modelling;• Simulation Modelling;• Education.

Systems Approach• Formulation

– To detect and formulate the problem;• Modelling

– To better understand the behaviour of the system under study, its bottlenecks in particular;

• Evaluation– To analyse the system behaviour through quantitative

MOP and find alternative ways to operate the system;• Decision

– To select the best alternative according to system goals.

Decomposition Approach• Reduces complexity;• Divides the system under study into its components;• Studies the systems components in greater detail;• Allows modellers to develop a detailed model of the

bottlenecks in the system under study;• Allows analysts to study in greater detail those

components of the system, which malfunction;• Corrects the behaviour of the malfunctioning system;• Captures the global impact of operations in a

network.

Analytical Modelling

• Deterministic Models;

• Queueing Systems such as: – M/M/m; M/G/m.

• Queueing Networks such as: – Parallel, in series; open or closed circuit networks.

Deterministic Models J. Pachl

, where - minimum number of tracks; - average dwell time in minutes per train;- average traffic flow, trains per period.

average

trainsaveragedwelltracks t

ntn

*,min,

min,tracksn

averagedwellt ,

average

trains

t

n

Queueing Systems

Expected freight trains in queue (G/G/m queue)

Queueing Networks I

Receiving Yard

Classification Yard

λin

Departure Yard

Workshop

λout

Car Yard (Rip Tracks)

Legend: in –input freight trains; in – input locomotives out –output freight trains; out – output locomotives T and t – refer to sections “Times at Formation Yard”

λin,loco

tAY arriving, TAYwaiting , TAY service

TSZwaiting , TSZ service TDY

waiting, TDYservice, tDY

waiting-dep., tDYdeparture

tWSarriving T

WSidle t

WSwaiting-inspection t

WSinspection t

WSwaiting-departure t

WSdeparture

Rail Freight Yard

λout,loco

Queueing Networks II• The parameter αj is λ0 * q0j, where λ0 is arrivals from

outside with probability q0j;

• The required λi are obtained by linear equations written for λj, as follows:

iiQSiiQSiQSiQSi

nQSnQSQSQS

nQSnQSQSQS

ppp

ppp

ppp

,112,21,1

,23,231,2122

,13,132,1211

*...**

.

.

.

*...**

*...**

Simulation Modelling I

Generator n freight trains

Storage Area “rail network” infinite capacity

Arrival Yard (AY) Cutting locomotive (x gn) & Shunting man

Classification (x gn) & Classifications man

Inspection (x gn) & Inspections man

Further operations in AY (x gn)

Shunting Zone (SZ) Breaking Down (x 1) & Yard Crew

Making up (x 1) & Yard Crew

Storage Area in SZ finite capacity (n tracks)

Car Yard (CY)

Storage Area in CY finite capacity

(n tracks)

Work center in CY (x 1) “Rip Tracks”

Departure Yard (DY) Inspection for departure (x gn) & Inspections man

Train-engine operations (x gn) & Road Crew

Storage Area for re-breaking

down

Leaving Formation Yard (LFY)

Storage Area in LFY finite capacity (n leads)

LFY adjoining section (x gn)

Dispatch

SIMUL 8 attributes:

Work Entry Points – generate freight trains;

Work Centres – replicate where operations with trains are executed;

Storage Areas – replicate the limited number of tracks;

Work Exit Points – indicate where the freight trains leave the yard;

Floating Resources – replicate the yard personnel behaviour.

Simulation Modelling II

SIMUL 8 attributes:

n, Work Entry Points – generate freight trains;

n, Work Centres – replicate where operations with trains are executed;

n, Storage Areas – replicate the limited number of tracks;

n, Work Exit Points – indicate where the freight trains leave the yard;

n, Floating Resources – replicate the yard personnel behaviour.

Simulation Modelling III

Simulation Modelling IV

Simulation Modelling V • Arena Attributes • Freight Trains are represented by entities• Flow of the entities through the system can be

captured• Entities are created by a create module• Process Module• Decide Module • Dispose Module• Model Reports

Simulation Modelling VI

Simulation Modelling VII

Simulation Modelling VIII

Thank you for your attention

Dr Marin Marinov

[email protected]

Clare Woroniuk

[email protected]