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Revision 62008-03-01 - TWikiAdminUser

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META TOPICPARENT	name="SubmitCaseStudy"

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Operations Research Topics:

Application Areas:

Problem Description

THE NETWORK DESIGN PROBLEM

Adapted from a real world problem

Before undertaking this case study you must (at least) read the DataNetworkFlows case study to learn about the components that make up Storage Area Networks (SANs).

The company that commissioned the initial research on routing their data (see DataNetworkFlows) has decided to add another storage device (Device C) to their network. They have also performed some extensive data traffic measurement and determined the actual data flow requirements they need to support. These flows are shown in Table 1.

Source	Destination	Requirement Mb/s
Host 1	Device A	65
Host 1	Device B	50
Host 1	Device C	30
Host 2	Device A	25
Host 2	Device B	70
Host 3	Device A	35
Host 3	Device C	65

They estimate they will need either an extra hub or an extra switch or some combination of the 3 hubs and 2 switches. They commissioned the same network consultant to design their new network for them. He finished the job, but left for his honeymoon before writing a management summary or documenting his work. The files he left are contained in:

??? LINK ??? san_design.zip

The company want to use these files to find the optimal SAN design that will support their data flow requirements.

For more detail see A Mixed-Integer Approach to Storage Area Network Design using Generic Network Components, O’Sullivan and Walker Engineering Science Technical Report 626, March 2006

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STUDENT TASKS


1. Comment the AMPL files san_design_neos.mod, san_design.dat and san_design_neos.run from san_design.zip. Run these files to find the optimal SAN design to support the flow requirements. Write a management summary for your solution.

What to hand in   ??? Mike to look at??? You commented AMPL files. Your management summary.


Extra for Experts' Tasks


1. One problem that often arises in network design (and other mixed-integer programming) is that of symmetry. If components in the network have the same properties, then mixed-integer programming will consider all the combinations of these components even though many combinations represent the same network. The following constraints:

subject to LinkAntisymmetry {l in LINKS} :
  card({k in LINKS : (from[k] = from[l]) and (to[k] = to[l]) and
                     (ord(k) > ord(l))}) * UseLink[l] >=
  sum {k in LINKS : (from[k] = from[l]) and (to[k] = to[l]) and
                    (ord(k) > ord(l))} UseLink[k];
  
subject to HubAntisymmetry {h in HUBS} :
  card({g in HUBS : ord(g) > ord(h)}) * UseHub[h] >=
  sum {g in HUBS : ord(g) > ord(h)} UseHub[g];

subject to SwitchAntisymmetry {s in SWITCHES : s <> last(SWITCHES)} :
  card({t in SWITCHES : ord(t) > ord(s)}) * UseSwitch[s] >=
  sum {t in SWITCHES : ord(t) > ord(s)} UseSwitch[t];


can be used to remove symmetry from the SAN design problem if all the hubs, switches and links have the same properties (i.e., bandwidth capacity, number of port slots, etc).

Add these constraints to san_design_neos.run and solve the SAN design problem again. Describe how these constraints remove symmetry. Comment on their effect on the solver's progress.

What to hand in  A brief (1 page or less) summary comprised of your description of how the antisymmetry constraints work and their effect on the solver's progress.
-->

Revision 52008-03-01 - TWikiAdminUser

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META TOPICPARENT	name="SubmitCaseStudy"

<-- Under Construction -->

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Operations Research Topics:

Application Areas:

Problem Description

THE NETWORK DESIGN PROBLEM

Adapted from a real world problem

Before undertaking this case study you must (at least) read the DataNetworkFlows case study to learn about the components that make up Storage Area Networks (SANs).

The company that commissioned the initial research on routing their data (see DataNetworkFlows) has decided to add another storage device (Device C) to their network. They have also performed some extensive data traffic measurement and determined the actual data flow requirements they need to support. These flows are shown in Table 1.

Source	Destination	Requirement Mb/s
Host 1	Device A	65
Host 1	Device B	50
Host 1	Device C	30
Host 2	Device A	25
Host 2	Device B	70
Host 3	Device A	35
Host 3	Device C	65

They estimate they will need either an extra hub or an extra switch or some combination of the 3 hubs and 2 switches. They commissioned the same network consultant to design their new network for them. He finished the job, but left for his honeymoon before writing a management summary or documenting his work. The files he left are contained in:

??? LINK ??? san_design.zip

The company want to use these files to find the optimal SAN design that will support their data flow requirements.

For more detail see A Mixed-Integer Approach to Storage Area Network Design using Generic Network Components, O’Sullivan and Walker Engineering Science Technical Report 626, March 2006

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1. Comment the AMPL files san_design_neos.mod, san_design.dat and san_design_neos.run from san_design.zip. Run these files to find the optimal SAN design to support the flow requirements. Write a management summary for your solution.

What to hand in ??? Mike to look at??? You commented AMPL files. Your management summary.

Extra for Experts' Tasks

1. One problem that often arises in network design (and other mixed-integer programming) is that of symmetry. If components in the network have the same properties, then mixed-integer programming will consider all the combinations of these components even though many combinations represent the same network. The following constraints:

subject to LinkAntisymmetry {l in LINKS} :
  card({k in LINKS : (from[k] = from[l]) and (to[k] = to[l]) and
                     (ord(k) > ord(l))}) * UseLink[l] >=
  sum {k in LINKS : (from[k] = from[l]) and (to[k] = to[l]) and
                    (ord(k) > ord(l))} UseLink[k];
  
subject to HubAntisymmetry {h in HUBS} :
  card({g in HUBS : ord(g) > ord(h)}) * UseHub[h] >=
  sum {g in HUBS : ord(g) > ord(h)} UseHub[g];

subject to SwitchAntisymmetry {s in SWITCHES : s <> last(SWITCHES)} :
  card({t in SWITCHES : ord(t) > ord(s)}) * UseSwitch[s] >=
  sum {t in SWITCHES : ord(t) > ord(s)} UseSwitch[t];

can be used to remove symmetry from the SAN design problem if all the hubs, switches and links have the same properties (i.e., bandwidth capacity, number of port slots, etc).

Add these constraints to san_design_neos.run and solve the SAN design problem again. Describe how these constraints remove symmetry. Comment on their effect on the solver's progress.

What to hand in A brief (1 page or less) summary comprised of your description of how the antisymmetry constraints work and their effect on the solver's progress.

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META FORM	name="OpsRes.CaseStudyForm"
FORM FIELD Title	Title	ANetworkDesignProblem
FORM FIELD DateSubmitted	DateSubmitted	20 Feb 2008

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FORM FIELD CaseStudyType	CaseStudyType	DIYCaseStudy

FORM FIELD OperationsResearchTopics	OperationsResearchTopics
FORM FIELD ApplicationAreas	ApplicationAreas

|*FORM FIELD ProblemDescription*|ProblemDescription|*THE NETWORK DESIGN PROBLEM*

Adapted from a real world problem

Before undertaking this case study you must (at least) read the DataNetworkFlows case study to learn about the components that make up Storage Area Networks (SANs).

The company that commissioned the initial research on routing their data (see DataNetworkFlows) has decided to add another storage device (Device C) to their network. They have also performed some extensive data traffic measurement and determined the actual data flow requirements they need to support. These flows are shown in Table 1.

Source	Destination	Requirement Mb/s
Host 1	Device A	65
Host 1	Device B	50
Host 1	Device C	30
Host 2	Device A	25
Host 2	Device B	70
Host 3	Device A	35
Host 3	Device C	65

They estimate they will need either an extra hub or an extra switch or some combination of the 3 hubs and 2 switches. They commissioned the same network consultant to design their new network for them. He finished the job, but left for his honeymoon before writing a management summary or documenting his work. The files he left are contained in:

??? LINK ??? san_design.zip

The company want to use these files to find the optimal SAN design that will support their data flow requirements.

For more detail see A Mixed-Integer Approach to Storage Area Network Design using Generic Network Components, O’Sullivan and Walker Engineering Science Technical Report 626, March 2006 |

Revision 42008-02-23 - MichaelOSullivan

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Revision 32008-02-20 - LaurenJackson

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Revision 22008-02-20 - LaurenJackson

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Revision 12008-02-20 - LaurenJackson

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META TOPICPARENT	name="SubmitCaseStudy"

<-- This template controls both the look and functionality of case study topics. You should not need to alter the layout, only edit the data using the form above.

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Set VIEW_TEMPLATE = CaseStudyView

Comment out the next line to use the TWiki default edit

Set EDIT_TEMPLATE = CaseStudyEdit

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<--
This topic can only be changed by: 
 Set ALLOWTOPICCHANGE = TWikiAdminGroup, MaintenanceGroup, ContributorGroup
 
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Case Study: ANetworkDesignProblem

Submitted: 20 Feb 2008

Operations Research Topics:

Application Areas:

Problem Description

THE NETWORK DESIGN PROBLEM

Adapted from a real world problem

Before undertaking this case study you must (at least) read the DataNetworkFlows case study to learn about the components that make up Storage Area Networks (SANs).

The company that commissioned the initial research on routing their data (see DataNetworkFlows) has decided to add another storage device (Device C) to their network. They have also performed some extensive data traffic measurement and determined the actual data flow requirements they need to support. These flows are shown in Table 1.

Source	Destination	Requirement Mb/s
Host 1	Device A	65
Host 1	Device B	50
Host 1	Device C	30
Host 2	Device A	25
Host 2	Device B	70
Host 3	Device A	35
Host 3	Device C	65

They estimate they will need either an extra hub or an extra switch or some combination of the 3 hubs and 2 switches. They commissioned the same network consultant to design their new network for them. He finished the job, but left for his honeymoon before writing a management summary or documenting his work. The files he left are contained in:

??? LINK ??? san_design.zip

The company want to use these files to find the optimal SAN design that will support their data flow requirements.

For more detail see A Mixed-Integer Approach to Storage Area Network Design using Generic Network Components, O’Sullivan and Walker Engineering Science Technical Report 626, March 2006

Return to top

Problem Formulation

The formulation...

Return to top

Computational Model

The computational model...

Return to top

Results

The results...

Return to top

Conclusions

In conclusion...

Return to top

Student Tasks

STUDENT TASKS

1. Comment the AMPL files san_design_neos.mod, san_design.dat and san_design_neos.run from san_design.zip. Run these files to find the optimal SAN design to support the flow requirements. Write a management summary for your solution.

What to hand in ??? Mike to look at??? You commented AMPL files. Your management summary.

Extra for Experts' Tasks

1. One problem that often arises in network design (and other mixed-integer programming) is that of symmetry. If components in the network have the same properties, then mixed-integer programming will consider all the combinations of these components even though many combinations represent the same network. The following constraints:

subject to LinkAntisymmetry {l in LINKS} :
  card({k in LINKS : (from[k] = from[l]) and (to[k] = to[l]) and
                     (ord(k) > ord(l))}) * UseLink[l] >=
  sum {k in LINKS : (from[k] = from[l]) and (to[k] = to[l]) and
                    (ord(k) > ord(l))} UseLink[k];
  
subject to HubAntisymmetry {h in HUBS} :
  card({g in HUBS : ord(g) > ord(h)}) * UseHub[h] >=
  sum {g in HUBS : ord(g) > ord(h)} UseHub[g];

subject to SwitchAntisymmetry {s in SWITCHES : s <> last(SWITCHES)} :
  card({t in SWITCHES : ord(t) > ord(s)}) * UseSwitch[s] >=
  sum {t in SWITCHES : ord(t) > ord(s)} UseSwitch[t];

can be used to remove symmetry from the SAN design problem if all the hubs, switches and links have the same properties (i.e., bandwidth capacity, number of port slots, etc).

Add these constraints to san_design_neos.run and solve the SAN design problem again. Describe how these constraints remove symmetry. Comment on their effect on the solver's progress.

What to hand in A brief (1 page or less) summary comprised of your description of how the antisymmetry constraints work and their effect on the solver's progress.

Return to top

META FORM	name="OpsRes.CaseStudyForm"
FORM FIELD Title	Title	ANetworkDesignProblem
FORM FIELD DateSubmitted	DateSubmitted	20 Feb 2008
FORM FIELD OperationsResearchTopics	OperationsResearchTopics
FORM FIELD ApplicationAreas	ApplicationAreas

|*FORM FIELD ProblemDescription*|ProblemDescription|*THE NETWORK DESIGN PROBLEM* Adapted from a real world problem

Before undertaking this case study you must (at least) read the ??? LINK??? Data Network Flows case study to learn about the components that make up Storage Area Networks (SANs).

The company that commissioned the initial research on routing their data (see ??? LINK??? Data Network Flows) has decided to add another storage device (Device C) to their network. They have also performed some extensive data traffic measurement and determined the actual data flow requirements they need to support. These flows are shown in Table 1.

Source	Destination <-- -->	Requirement Mb/s
Host 1	Device A	65
Host 2	Device A	25
Host 3	Device A	35
Host 1	Device B	50
Host 2	Device B	70
Host 1	Device C	30
Host 3	Device C	65

They estimate they will need either an extra hub or an extra switch or some combination of the 3 hubs and 2 switches. They commissioned the same network consultant to design their new network for them. He finished the job, but left for his honeymoon before writing a management summary or documenting his work. The files he left are contained in:

??? LINK ??? san_design.zip

The company want to use these files to find the optimal SAN design that will support their data flow requirements.

For more detail see A Mixed-Integer Approach to Storage Area Network Design using Generic Network Components, O’Sullivan and Walker Engineering Science Technical Report 626, March 2006 |

FORM FIELD ProblemFormulation	ProblemFormulation	The formulation...
FORM FIELD ComputationalModel	ComputationalModel	The computational model...
FORM FIELD Results	Results	The results...
FORM FIELD Conclusions	Conclusions	In conclusion...
FORM FIELD ExtraForExperts	ExtraForExperts

|*FORM FIELD StudentTasks*|StudentTasks|*STUDENT TASKS*

1. Comment the AMPL files san_design_neos.mod, san_design.dat and san_design_neos.run from san_design.zip. Run these files to find the optimal SAN design to support the flow requirements. Write a management summary for your solution.

What to hand in You commented AMPL files. Your management summary.

Extra for Experts' Tasks

1. One problem that often arises in network design (and other mixed-integer programming) is that of symmetry. If components in the network have the same properties, then mixed-integer programming will consider all the combinations of these components even though many combinations represent the same network. The following constraints:

subject to LinkAntisymmetry {l in LINKS} :
  card({k in LINKS : (from[k] = from[l]) and (to[k] = to[l]) and
                     (ord(k) > ord(l))}) * UseLink[l] >=
  sum {k in LINKS : (from[k] = from[l]) and (to[k] = to[l]) and
                    (ord(k) > ord(l))} UseLink[k];
  
subject to HubAntisymmetry {h in HUBS} :
  card({g in HUBS : ord(g) > ord(h)}) * UseHub[h] >=
  sum {g in HUBS : ord(g) > ord(h)} UseHub[g];

subject to SwitchAntisymmetry {s in SWITCHES : s <> last(SWITCHES)} :
  card({t in SWITCHES : ord(t) > ord(s)}) * UseSwitch[s] >=
  sum {t in SWITCHES : ord(t) > ord(s)} UseSwitch[t];

can be used to remove symmetry from the SAN design problem if all the hubs, switches and links have the same properties (i.e., bandwidth capacity, number of port slots, etc).

Add these constraints to san_design_neos.run and solve the SAN design problem again. Describe how these constraints remove symmetry. Comment on their effect on the solver's progress.

What to hand in A brief (1 page or less) summary comprised of your description of how the antisymmetry constraints work and their effect on the solver's progress.|

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Revision 72008-04-02 - TWikiAdminUser

Computational Model

Computational Model

Results

Results

Conclusions

Conclusions

Revision 62008-03-01 - TWikiAdminUser

Operations Research Topics:

Application Areas:

Contents

Problem Description

Problem Formulation

Computational Model

Results

Conclusions

Revision 52008-03-01 - TWikiAdminUser

Operations Research Topics:

Application Areas:

Contents

Problem Description

Problem Formulation

Problem Formulation

Computational Model

Computational Model

Results

Conclusions

Results

Conclusions

Student Tasks

Revision 42008-02-23 - MichaelOSullivan

Revision 32008-02-20 - LaurenJackson

Revision 22008-02-20 - LaurenJackson

Revision 12008-02-20 - LaurenJackson

Case Study: ANetworkDesignProblem

Submitted: 20 Feb 2008

Operations Research Topics:

Application Areas:

Contents

Problem Description

Problem Formulation

Computational Model

Results

Conclusions

Student Tasks