Six Minute Solutions #14

[S28]

Quick question for anyone who's familiar in resource scheduling...

For anyone who doens't have this problem in front of them, the author asks gives a CPM schedule and asks us to calculate which week will utilize the most resources if every activity starts at the earliest possible time? Author also gives the list of activities and the corresponding resources per activity.

The author adds up the resources per week each of the four weeks during the project, but what I don't get is he only gives credit to each activity once throughout the week.

I.E. his answer is Week 1, in which activities AB (7 resources), BC (5 resources), and BD (16 resources) are implemented, so he calculates week 1 to be 28.

But if you add up the resources every day, throughout the week, instead of just giving credit to those resources once per week, you would get a different answer.... So when it comes to resource scheduling, is the answer always going to be like the author found it here? Or are there instances where you could add up the resources per day throughout that said week?

Sorry if this is confusing, I'd just post the problem although I'm fairly new around here and don't know what the procedure is for copyright, etc...

Thanks.

 

[desantmf]

S28, I would have to look at the question, however it sounds like the way the question is written it gives you resources per week per activity, NOT per day. Which allows you to just add up all the resources used once per week.

Also to answer the question, about "is the answer always going to be like the author found it here". No - it depends how the question is written.

I am sure if you scan in the problem we can help more.

 

[S28]

Attached is the problem in question. Hopefully this will help everyone.

Thanks again!

ResourceSchedulingExample.pdf

 

[togapilot]

The resource given is "people" not "people-days" as you're suggesting. In other words, for AB, the amount of resources (people) that are consumed by the task and will not be available for any other task until AB is complete is 7.

Hope that helps.

 

[bradlelf]

See if this helps ...

ACTIVITY No. of Resources DAY A-B B-C C-D B-D D-E C-F E-F E-G F-G Week 1 1 7 7 2 7 7 3 7 7 4 7 7 5 5 16 21 6 5 16 21 7 5 16 21 Week 2 8 5 5 9 5 5 10 5 5 11 5 5 12 5 5 13 11 7 18 14 11 7 18 Week 3 15 11 7 18 16 11 7 18 17 11 7 18 18 6 7 13 19 6 6 20 6 6 21 6 6 Week 4 22 6 9 15 23 6 9 15 24 6 9 15 25 6 9 15 26 6 9 15 27 6 9 15 28 6 6 Week 5 29 6 6 30 6 6 31 5 5 32 5 5 33 5 5 34 5 5 35 5 5 Week 6 36 5 5 37 5 5 38 0 39 0 40 0 41 0 42 0

 

[bradlelf]

So .. how exactly are we supposed to attach PDFs now?

 

[bradlelf]

Ok, I got it. See if this works ...

Problem 14.pdf

 

[togapilot]

@bradlelf I assume 1 week = 5 days unless you're we're given overtime information.

 

[bradlelf]

@togapilot I did not assume because it did not say 5 day work week. This is a very ambiguous question and it should have clarified; but absent the statement "assume a 5 day work week" I would take "week" to mean 7 days.

I think I am correct because in a "5 day work week" both Week No. 1 and 2 would have a resource need of 21. The answer could not be A and B, concurrently.

 

[S28]

The author uses work week's of 7 days as bradlelf is suggesting. Author's answer is A, 28 days.

He says...

Week 1 includes activities AB, BC< and BD for resource totals of 7+5+16=28

Week 2 includes activities BC, CD, and CF with resource totals of 5+11+7=23

Week 3 includes activities CD, DE, and CF with resource totals of 11+6+7=24

Week 4 includes activities EF and EG, with resource totals of 6+9 = 15.

 

[PE_4_Panda]

Thanks @bradlelf for the explaination. I was confused as well.

 

[IlPadrino]

This looks like a poorly worded problem. You have to interpret what "most resources" means where "resources" is later defined to be "number of people". So which week uses the "most" number of people? And what is a "week"?

I like bradlelf's interpretation that "most" means the most number of people concurrently on the job. This is one aspect of resource leveling which is the class of problem this appears to be.

I wouldn't worry too much about this particular problem. The exam questions are generally better written (they've got better QC!) and don't generally require assumptions about definitions unless they're industry standard.