I tried instead of a double constraint a triple constraint using consumable resources functionality and it worked as expected, then disabled resource leveling on quarterly budget and the schedule duration was reduced as expected.
I considered a variable consumable limit per month [20,000 max for Jan; 10,000 max for Feb; thereafter unrestricted], a consumable limit per quarter [50,000 1st Q thereafter unrestricted] and a total consumable limit [250,000], no additional functionality is needed. Budget for Activity A equal to 100,000.
Note how the budget scheduled to be spent during March increased as no longer the quarterly amount was driving.
I would like for the model to be easier to prepare, if instead of using activities for material creation I could create material production using fixed dates instead of activity driven it would be easier to create and update, both options are available for regular renewable resource but not for consumable resource.
It is a single activity model, just imagine when multiple activities are competing for the same consumable resources !
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21 years 7 months
Member for21 years8 months
Submitted by Rafael Davila on Fri, 2015-02-06 01:44
I understood the double constrained example as a consumable resource with a maximum available consumable amount per month (can be a different maximum for each month) and a limit on the total cumulative amount allowed to be consumed.
For example a total budget of 100,000 with 20,000 as the maximum amount you can spend per month.
You will be allowed to spend 20,000 every month for 5 months before your budget is depleted.
You will be allowed to spend 10,000 per month for 10 months before your budget is depleted.
You will be allowed any combination that meets both criteria.
If an activity requires a monthly expenditure that will break the monthly limit a portion will be delayed for next month. If an activity breaks the limit on the cumulative amount allowed or budgeted it will be delayed until more funds are available.
Double constrained resource can also be in hours, say you will be allowed to use certain resource for up to 100 hours per month with a maximum budgeted hours of 1,000.
Member for
24 years 8 months
Member for24 years9 months
Submitted by Vladimir Liberzon on Wed, 2015-02-04 17:31
I would not call total budget as the resource. I understood double constrained as renewable resources with different available quantity at different periods. So this is not the separate resource type.
Member for
21 years 7 months
Member for21 years8 months
Submitted by Rafael Davila on Wed, 2015-02-04 12:35
No doubt loss of production time can be very costly. A well known fact that is usually tackled with the use of contractual penalties. But this can be a two edged sword, building in a hurry can have a negative impact on quality.
Usually pharmaceuticals deal with both issues, time and quality, by means of the appropriate contract agreements. Instead of using fixed price agreement they resort to the Project Management contract type. The use of established PM companies works well, here they get the needed time and quality results. Pharmaceutical construction jobs are usually of relatively short duration because of the huge cost on loss of production days that will never be recovered. The success of the job is not automatically solved by magic scheduling, the selection of the contract type as well as the team of PM and Contractors is also critical.
Anyway, from the point of view of the Owner of the job frequently he shall analyze the time impact on his job and manage the job with this consideration. Time is money and the consideration of planning activities and entire jobs shall considering time dependent availability of funds, the inflation impact on cost as well as the impact on net present value and the internal rate of return. They need software capable of assisting them with such analysis.
Doubly constrained resources are constrained on a periodic basis, similar to renewable resources, as well as for the total project duration, as with the consumable resources. An example is a total budget with an extra restriction of a maximum limit per period.
These resource types cannot be modeled in any way using the traditional resource types, make sure your software is capable enough.
Member for
21 years 7 monthsVladimir,I tried instead of a
Vladimir,
I tried instead of a double constraint a triple constraint using consumable resources functionality and it worked as expected, then disabled resource leveling on quarterly budget and the schedule duration was reduced as expected.
I considered a variable consumable limit per month [20,000 max for Jan; 10,000 max for Feb; thereafter unrestricted], a consumable limit per quarter [50,000 1st Q thereafter unrestricted] and a total consumable limit [250,000], no additional functionality is needed. Budget for Activity A equal to 100,000.
Note how the budget scheduled to be spent during March increased as no longer the quarterly amount was driving.
I would like for the model to be easier to prepare, if instead of using activities for material creation I could create material production using fixed dates instead of activity driven it would be easier to create and update, both options are available for regular renewable resource but not for consumable resource.
It is a single activity model, just imagine when multiple activities are competing for the same consumable resources !
Member for
21 years 7 monthsI understood the double
I understood the double constrained example as a consumable resource with a maximum available consumable amount per month (can be a different maximum for each month) and a limit on the total cumulative amount allowed to be consumed.
For example a total budget of 100,000 with 20,000 as the maximum amount you can spend per month.
Double constrained resource can also be in hours, say you will be allowed to use certain resource for up to 100 hours per month with a maximum budgeted hours of 1,000.
Member for
24 years 8 monthsI would not call total budget
I would not call total budget as the resource. I understood double constrained as renewable resources with different available quantity at different periods. So this is not the separate resource type.
Member for
21 years 7 monthsNo doubt loss of production
No doubt loss of production time can be very costly. A well known fact that is usually tackled with the use of contractual penalties. But this can be a two edged sword, building in a hurry can have a negative impact on quality.
Usually pharmaceuticals deal with both issues, time and quality, by means of the appropriate contract agreements. Instead of using fixed price agreement they resort to the Project Management contract type. The use of established PM companies works well, here they get the needed time and quality results. Pharmaceutical construction jobs are usually of relatively short duration because of the huge cost on loss of production days that will never be recovered. The success of the job is not automatically solved by magic scheduling, the selection of the contract type as well as the team of PM and Contractors is also critical.
Anyway, from the point of view of the Owner of the job frequently he shall analyze the time impact on his job and manage the job with this consideration. Time is money and the consideration of planning activities and entire jobs shall considering time dependent availability of funds, the inflation impact on cost as well as the impact on net present value and the internal rate of return. They need software capable of assisting them with such analysis.
http://www.pmknowledgecenter.com/node/104