Handout 5_2010 - 1 IE 372 Simulation - Handout 5 ADDITIONAL...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 IE 372 Simulation - Handout 5 ADDITIONAL SIMAN CAPABILITIES Blocks and elements discussed so far constitute about 20% of SIMAN constructs, but over 50% of modeling requirements can be met with these. For the rest, we need to learn additional constructs. Additional Resource Features ALTER: Resource ID {-}, Capacity Change { 1 }: repeats; (block) Function: Changes the capacity of the resource by “Capacity Change” which can be negative. If the resource is busy at the time of change, change takes effect when resource units are released. Example 1: A factory is operational 24 hours a day. Two machines are available in the first 16 hours, and one machine in the last 8 hours. If both machines are busy at the end of the 16 hours, they will continue processing and the one that finishes its part earlier will stop until the starting time next day. RESOURCES: Machine,CAPACITY(2); MR(Machine)=2 CREATE: EXPO(0.4); Part processing QUEUE, MachineQ; SEIZE, 2: Machine,1; DELAY: TRIA(0.2,0.3,0.5); Times in hours RELEASE: Machine,1; DISPOSE; CREATE, 1,16: 24; Capacity change COUNT: Days,1; SEIZE, 1: Machine,1; ALTER: Machine,-1; MR(Machine)=1 RELEASE: Machine,1; Change takes effect DELAY: 24*NC(Days)-TNOW ; ALTER: Machine,1; MR(Machine)=2 DISPOSE;
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Suppose both machines are busy at time 16, and a part releases one of the machines at time 16.5. Then, the first capacity change entity can seize the machine at time 16.5, and the machine capacity will be one for the next 24*1-16.5=7.5 hours. It will be set to two at time 16.5+7.5=24 and remain so at least until the second capacity change entity arrives at time 16+24=40. See also the SCHEDULES element. SELECT, Resource Selection Rule { POR }: Seize Label {-}: repeats; (block) Function: Selects one of the non-identical resources according to the “Resource Selection Rule”. “Resource Selection Rule” can be one of the following. - POR: preferred order rule - CYC: cyclic - RAN: random - LNB: largest number busy - SNB: smallest number busy - LRC: largest remaining capacity - SRC: smallest remaining capacity Example 2: Between two types of machines, A and B, select the one having the smallest number busy. CREATE: EXPO(12); QUEUE, CommonQ; SELECT, SNB: MacA: MacB; MacA SEIZE: MachineA; --- --- MacB SEIZE: MachineB; --- --- Queue Arrivals SELECT Resource 2 Resource 1
Background image of page 2
3 PREEMPT, Priority { 1 }: Resource ID {-}, Attribute ID { Stored internally }, Destination Label { Held internally for reallocation }; (hold block) Function: Preempts a resource regardless of whether it is busy or idle. “Priority” is the priority of the PREEMPT block among other PREEMP blocks competing for the same resource. (Note that a PREEMPT block always has higher priority than a SEIZE block.) Remaining process delay of the preempted entity is stored in “Attribute ID”, and the preempted entity is sent to the block having “Destination Label”. Example 3: A machine with breakdowns.
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 25

Handout 5_2010 - 1 IE 372 Simulation - Handout 5 ADDITIONAL...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online