Merely hitting the resource leveling key is not enough to make your software resource leveling to be optimal or near optimal as true optimal might be missed or in complicated schedules you will never know. Near optimal at the present state of knowledge is enough, unfortunately operations research scientist have not reached to a 100% optimal algoritm. The best you can do is get software that consistently yields better results, and this you shall look for.
A 7 days schedule, obviously optimum solution as the unleveled schedule also takes 7 days. You should try it yourself.
Make sure your software resource leveling engine is good enough not only to provide better "optimal" schedules but also able to provide good prioritization control at different levels.
About mixing manual resource leveling with automatic resource leveling it is not considered good practice. For a reference on this issue click the following link.
if you are also going to later resource level your schedule ......
Finally, there must be no resource considerations in the logic used. This is sometimes called, “soft logic.” You do not want to codify resource timing considerations into your schedule if you are also going to later resource level your schedule. The two different procedures used together will only produce erroneous results.
Hitting the level button and saying "This is what we do because the schedule says so" will get you in trouble and not tracking pretty quickly. I agree with Diik in that you end up with a management tracking tool and an ignored field schedule.
In turnarounds I'll use a combination of both. I'll setup all known constraints based around contractor, machine, equipment, and project availability. I'll run a quick resource level to see the optimized schedule. After this, sitting down with the contractors and field engineers to manually find the best path as far as resources in same area, flow of equipment from one job to the next for the mobilization/demobilization and ensuring any potential discovery is front loaded. Those are all things optimizing can't know or correct. You can optimize using priorities but in the end I can't see ever getting away from real work knowledge and manual tweaking after that; it's all part of the toolbox we use to get the job done.
Member for
24 years 9 months
Member for24 years9 months
Submitted by Vladimir Liberzon on Thu, 2012-06-28 01:24
If resource-leveled schedules make most tasks critical or near-critical (using up most of the float in the process) then your resources are loaded in most effective way (idle time is minimized).
We already discussed manual leveling. It could be fine but it can be confirmed only by comparing manual schedule with the optimized schedule created by the software tool. And manual rescheduling after entering actual data is time consuming.
When we first time applied resource optimization in turnaround project at refinery plant and the project was successfully finished, we asked project manager if he saw advantages in using our software for resource management. An answer was "Yes, certainly! It was the first time when everything was done in available time window." If you are disappointed with software application for project resource management then it may be two options: 1) software was not applied properly, 2) you used wrong software.
We prefer to set manpower hiring levels based on a well-sequenced and priritized schedule, which has been prepared with field supervisors' input. This results in a workable schedule that field forces can accept.
Most resource-leveled schedules result in unworkable schedules since they make most tasks critical or near-critical (using up most of the float in the process). They also result in a disruptive work flow, just to accomodate resource usage.
We use a different approach, that has proven practical and effective in countless turnarounds. We notice that most resource-leveled schedules we have seen end up being used mainly for reporting to management; they are almost never used to help the field forces organize their work. So field forces will complete the turnaround without schedules, just not very efficiently.
Could this be one of the elements that result in failed turnarounds? All who have polled the industry agree that about 70% or more turnarounds end up in failure (extended schedules, huge cost overruns).
Member for
21 years 8 months
Member for21 years8 months
Submitted by Rafael Davila on Wed, 2012-06-27 21:32
manual leveling does not guarantee good results, the software can estimate much more options but requires good project model where all schedule constraints are entered.
Besides, the situations are changing and the order of activities that was optimal yesterday may be far from optimal today.
Schedule recalculation is easy with the software resource leveling but manual resequencing of future works each time when actual data are entered is impossible. Applying priorities is fine if you can compare prioritized schedule with the optimal.
Member for
21 years 8 months
Member for21 years8 months
Submitted by Rafael Davila on Wed, 2012-06-27 02:16
Usually at first what-if with software that allows for Phase Priority to take precedence over Activity Priority will give you the control you need.
If your urge for certain order is BIG then do not use optimization methods that might override some priorities in search for the optimum defined as of shorter duration, consider using Standard algorithms.
As you can see optimal is not the same for everyone and you shall select among the several algorithms available.
Look at the following schedule. All activities can occur at the same time, there are no links, only resource constraints. All activities sharing a same resource but higher priorities at phase level take precedence, then activity level will follow. Higher numeric value meaning higher priority.
Just imagine trying to do this manually in construction jobs where you frequently have partial assignments of multiple crews on each activity and shared equipment at different ratios. Like for example 100% of time formwork crew, 25% Electrical and Plumbing crews plus crane 50% of the day and this different on hundreds of activities.
I play Pampers Little Leagues, 700 activities per job is my average, still too complicated for ancient manual adjustments.
One problem with "automatic" resource leveling is that it generally makes most tasks critical or near-critical, which may be confusing to the field supervisors. Additionally, if tasks are not sequenced logically, then the schedule may result in a disruptive work flow, with extra movement (mobilization/demobilization from one work item to the next, sometimes in unrelated parts of a process plant).
The best alternative is to sequence the work, in accordance with field supervisor's input and guidance, then prioritize the work. This will result in a better schedule for process plant shutdowns/turnarounds.
Member for
24 years 9 months
Member for24 years9 months
Submitted by Vladimir Liberzon on Mon, 2007-06-11 06:50
I did not try Workbench and Planview for quite a long time, so I will not discuss these packages and hope that somebody else will add an information on their resource levelling capabilities.
Microsoft Project has one single criterion for resource levelling (if not to count options like using or not activity priorities). This algorithm is not described - what you may find in MS Project Help describes different algorithm that was used before 2000.
So you can influence project schedule only manually using priorities and due dates. For large projects it is very hard to improve the schedule manually.
In Primavera and Open Plan you can select different priorities for resource assignments and through what if analysis find the solution that produce better results for current project.
In Spider Project there is an additional option that is called Optimization. If this option is selected then the software tries to improve created resource constrained schedule through iterative process using different criteria and their combinations. The schedule may become much shorter.
Besides different software can take into account different sets of constraints. For an example: project scheduling that considers financial and material supply constraints is supported only by Spider Project and partially by Open Plan (in this package you can set expense limits for time periods).
Member for
21 years 8 monthsMerely hitting the resource
Merely hitting the resource leveling key is not enough to make your software resource leveling to be optimal or near optimal as true optimal might be missed or in complicated schedules you will never know. Near optimal at the present state of knowledge is enough, unfortunately operations research scientist have not reached to a 100% optimal algoritm. The best you can do is get software that consistently yields better results, and this you shall look for.
From http://www.stottlerhenke.com/products/aurora/index.htm
Most systems use simple rules to select and schedule activities and assign resources to carry them out. Often, these schedules are far from optimal.
My solution to the sample schedule provided in the following reference; http://www.stottlerhenke.com/products/aurora/Turnaround/2009-10-01_Auro… is as follows.
A 7 days schedule, obviously optimum solution as the unleveled schedule also takes 7 days. You should try it yourself.
Make sure your software resource leveling engine is good enough not only to provide better "optimal" schedules but also able to provide good prioritization control at different levels.
About mixing manual resource leveling with automatic resource leveling it is not considered good practice. For a reference on this issue click the following link.
http://www.ronwinterconsulting.com/Implementing_Resource_Leveling.pdf
if you are also going to later resource level your schedule ......
Finally, there must be no resource considerations in the logic used. This is sometimes called, “soft logic.” You do not want to codify resource timing considerations into your schedule if you are also going to later resource level your schedule. The two different procedures used together will only produce erroneous results.
Member for
13 years 4 monthsHitting the level button and
Hitting the level button and saying "This is what we do because the schedule says so" will get you in trouble and not tracking pretty quickly. I agree with Diik in that you end up with a management tracking tool and an ignored field schedule.
In turnarounds I'll use a combination of both. I'll setup all known constraints based around contractor, machine, equipment, and project availability. I'll run a quick resource level to see the optimized schedule. After this, sitting down with the contractors and field engineers to manually find the best path as far as resources in same area, flow of equipment from one job to the next for the mobilization/demobilization and ensuring any potential discovery is front loaded. Those are all things optimizing can't know or correct. You can optimize using priorities but in the end I can't see ever getting away from real work knowledge and manual tweaking after that; it's all part of the toolbox we use to get the job done.
Member for
24 years 9 monthsIf resource-leveled schedules
If resource-leveled schedules make most tasks critical or near-critical (using up most of the float in the process) then your resources are loaded in most effective way (idle time is minimized).
We already discussed manual leveling. It could be fine but it can be confirmed only by comparing manual schedule with the optimized schedule created by the software tool. And manual rescheduling after entering actual data is time consuming.
When we first time applied resource optimization in turnaround project at refinery plant and the project was successfully finished, we asked project manager if he saw advantages in using our software for resource management. An answer was "Yes, certainly! It was the first time when everything was done in available time window." If you are disappointed with software application for project resource management then it may be two options: 1) software was not applied properly, 2) you used wrong software.
Member for
13 years 4 monthsWe prefer to set manpower
We prefer to set manpower hiring levels based on a well-sequenced and priritized schedule, which has been prepared with field supervisors' input. This results in a workable schedule that field forces can accept.
Most resource-leveled schedules result in unworkable schedules since they make most tasks critical or near-critical (using up most of the float in the process). They also result in a disruptive work flow, just to accomodate resource usage.
We use a different approach, that has proven practical and effective in countless turnarounds. We notice that most resource-leveled schedules we have seen end up being used mainly for reporting to management; they are almost never used to help the field forces organize their work. So field forces will complete the turnaround without schedules, just not very efficiently.
Could this be one of the elements that result in failed turnarounds? All who have polled the industry agree that about 70% or more turnarounds end up in failure (extended schedules, huge cost overruns).
Member for
21 years 8 monthsApplying priorities is fine
Applying priorities is fine if you can compare prioritized schedule with the optimal.
Of course, otherwise you are in limbo.
Member for
24 years 9 monthsDiick,manual leveling does
Diick,
manual leveling does not guarantee good results, the software can estimate much more options but requires good project model where all schedule constraints are entered.
Besides, the situations are changing and the order of activities that was optimal yesterday may be far from optimal today.
Schedule recalculation is easy with the software resource leveling but manual resequencing of future works each time when actual data are entered is impossible. Applying priorities is fine if you can compare prioritized schedule with the optimal.
Member for
21 years 8 monthsUsually at first what-if with
Usually at first what-if with software that allows for Phase Priority to take precedence over Activity Priority will give you the control you need.
If your urge for certain order is BIG then do not use optimization methods that might override some priorities in search for the optimum defined as of shorter duration, consider using Standard algorithms.
As you can see optimal is not the same for everyone and you shall select among the several algorithms available.
Look at the following schedule. All activities can occur at the same time, there are no links, only resource constraints. All activities sharing a same resource but higher priorities at phase level take precedence, then activity level will follow. Higher numeric value meaning higher priority.
Just imagine trying to do this manually in construction jobs where you frequently have partial assignments of multiple crews on each activity and shared equipment at different ratios. Like for example 100% of time formwork crew, 25% Electrical and Plumbing crews plus crane 50% of the day and this different on hundreds of activities.
I play Pampers Little Leagues, 700 activities per job is my average, still too complicated for ancient manual adjustments.
Member for
13 years 4 monthsOne problem with "automatic"
One problem with "automatic" resource leveling is that it generally makes most tasks critical or near-critical, which may be confusing to the field supervisors. Additionally, if tasks are not sequenced logically, then the schedule may result in a disruptive work flow, with extra movement (mobilization/demobilization from one work item to the next, sometimes in unrelated parts of a process plant).
The best alternative is to sequence the work, in accordance with field supervisor's input and guidance, then prioritize the work. This will result in a better schedule for process plant shutdowns/turnarounds.
Member for
24 years 9 monthsRE: Resource Leveling and
Hi Brian!
I did not try Workbench and Planview for quite a long time, so I will not discuss these packages and hope that somebody else will add an information on their resource levelling capabilities.
Microsoft Project has one single criterion for resource levelling (if not to count options like using or not activity priorities). This algorithm is not described - what you may find in MS Project Help describes different algorithm that was used before 2000.
So you can influence project schedule only manually using priorities and due dates. For large projects it is very hard to improve the schedule manually.
In Primavera and Open Plan you can select different priorities for resource assignments and through what if analysis find the solution that produce better results for current project.
In Spider Project there is an additional option that is called Optimization. If this option is selected then the software tries to improve created resource constrained schedule through iterative process using different criteria and their combinations. The schedule may become much shorter.
Besides different software can take into account different sets of constraints. For an example: project scheduling that considers financial and material supply constraints is supported only by Spider Project and partially by Open Plan (in this package you can set expense limits for time periods).
Regards,
Vladimir