3rd Week Network Models

geograpical locations -> node (represented by a circle)

Route -> arc

• Origin Node -> has set capacities (might be increasavle by overtime)

• Destination Mode -> has set demands

• Arc (Route) .> das upper limits (arc capacity)

Decision Variables are usually called flow and represent the amounts shipped on the arcs they can contain unit shipping costs

• shipping cost can also include unt ptoduction cost at each plant

• capacities (or supplies)

• demands (or requirements)

• unit shipping (and production) cost

For variables:

• Final Value = shipped quantity

• Reduced Cost

  • 0 = used route

  • 0 = unused route; cost must drop this much to be used

• Allowable Increase/Decrease = how much shipping cost can change without changing which routes are used

For constraints:

• Shadow Price = value of one extra unit of capacity (or one extra unit of demand)

• Binding constraint → non-zero shadow price

• Non-binding → shadow price = 0

• Allowable Increase/Decrease = how far RHS can move before basis changes

Transshipment point 0 = TotalInflow - Total Outflow

Net Inflow = Total Inflow - Total Outflow

NetOutlow = Total outflow - Total Inflow

Origin: Positive NetOutflow <= Cap

Destination: PositiveInflow >= Demand