- "So, the use of 80% capacity for labor resources is not ungrounded."
The issue is how you tackle it, not always all employees or a particular employee work at 80%, not always it rains. It is better to handle probable reduced capacity if using buffers. If a contractor, for rain impact you shall use separate contract schedule that includes your risk for rain delays using calendars as proposed by most schedulers, for day to day management it is better to use a tight schedule that does not includes any padding.
Member for
15 years 9 months
Member for15 years9 months
Submitted by Johannes Vandenberg on Sat, 2016-04-30 09:45
A rule of thumb in Netherlands is that a worker at a 40 hour work week on average 1650 hours a year at work is present. This is explained in the following calculation.
Calculating the number of working days and hours:
An employed an average of 52 days per year was not present. This 52 non-workable days consist of 5 Bank Holidays , 25 days for vacation , 5 days for education , 13 random days off. These are usually utilized to bridge the gap between the bank holidays, such as the twee weeks during Christmas and New year, the period around Easter, and an average of 4 sick days.
per year (52 weeks x 5 working days) = 260 available work days
per year (260 available work days-52 non-workable days) = 208 workable days x 8 hours = 1664 hours
per month (208 workable days: 12 months) = average 17.3 workable days x 8 hours = 139 hours
per week (208 workable days: 52 weeks) = average 4 workable days x 8 hours = 32 hours
So, the use of 80% capacity for labor resources is not ungrounded.
My practice in scheduling is to carefully set up the project calendar in the scheduling models to reflect the project requirements at the start of the project.
Regards
Johannes
Member for
21 years 8 months
Member for21 years8 months
Submitted by Rafael Davila on Fri, 2016-04-29 18:08
The major problem with CPM software such as MSP and P6 is that they depend on fixed activity durations and this yields poor plans.
Activity durations depend on resource assignments and their relation to production rate of the hole crew, ths software shall be able to model this relationship.
The software shall adjust resource assignments for better use of limited resources.
When a resource is not temporarily available the activity does not necessarily stops it continues at a lower pace. If you plan for this you can get better plans.
When several resources are available to do the task the software shall select best assignment based on their different production rates and the impact on activity durations as well on total project duration.
Member for
21 years 8 months
Member for21 years8 months
Submitted by Rafael Davila on Fri, 2016-04-29 17:00
Top tip: Don’t allocate anyone at 100%. A full-time resource will still only be available to your project at 80% capacity because it’s the nature of the job that they will have other meetings to attend, training webinars to dial into, phone calls and lunch breaks that eat into their available time.
Very poor article and misleading. The strategy promotes inflating/padding activity durations in a non-transparent way, this should never be done as no-one will be able to know if there is a no buffer or a buffer and how much. By inflating the durations you promote Student Syndrome and Parkinson's law.
Usually only supervisors go to meetings and go to training webinars that eat into their available time while the crew continues doing its work. Lunch breaks are modeled as non-work time into their calendars. Making phone calls related to their task is part of their job.
Most full time resources will be available 100% of their estimated/average capacity [never use peak or minimum] except when in vacation or absent. Vacations can be modeled as a buffer or as a calendar exception. If vacations are random it can become very complicated, if all employees use same vacations days the calendar exception is the way to go. At home it is common to assign a Xmas vacation period for most jobs. If your software is P6 or MSP that cannot model variable quantity on resource assignments and the impact on production rate and activity duration then better use buffer approach.
These are basic principles used by several known methodologies that use buffer management approach such as Project Risk Analysis [PRA] and Critical Chain Project Management [CCPM].
I have a preference on Project Risk Analysis methods as it does not depend on buffer as a task, while CCPM model buffers as a task and assume feeding buffers are static, which is not true in most cases. Also CCPM does not provide a rational way to determine buffer amount while PRA do.
Member for
21 years 8 months- "So, the use of 80%
- "So, the use of 80% capacity for labor resources is not ungrounded."
The issue is how you tackle it, not always all employees or a particular employee work at 80%, not always it rains. It is better to handle probable reduced capacity if using buffers. If a contractor, for rain impact you shall use separate contract schedule that includes your risk for rain delays using calendars as proposed by most schedulers, for day to day management it is better to use a tight schedule that does not includes any padding.
Member for
15 years 9 monthsHi A rule of thumb in
Hi
A rule of thumb in Netherlands is that a worker at a 40 hour work week on average 1650 hours a year at work is present. This is explained in the following calculation.
Calculating the number of working days and hours:
An employed an average of 52 days per year was not present. This 52 non-workable days consist of 5 Bank Holidays , 25 days for vacation , 5 days for education , 13 random days off. These are usually utilized to bridge the gap between the bank holidays, such as the twee weeks during Christmas and New year, the period around Easter, and an average of 4 sick days.
So, the use of 80% capacity for labor resources is not ungrounded.
My practice in scheduling is to carefully set up the project calendar in the scheduling models to reflect the project requirements at the start of the project.
Regards
Johannes
Member for
21 years 8 monthsThe major problem with CPM
The major problem with CPM software such as MSP and P6 is that they depend on fixed activity durations and this yields poor plans.
Member for
21 years 8 monthsTop tip: Don’t allocate
Very poor article and misleading. The strategy promotes inflating/padding activity durations in a non-transparent way, this should never be done as no-one will be able to know if there is a no buffer or a buffer and how much. By inflating the durations you promote Student Syndrome and Parkinson's law.
Usually only supervisors go to meetings and go to training webinars that eat into their available time while the crew continues doing its work. Lunch breaks are modeled as non-work time into their calendars. Making phone calls related to their task is part of their job.
Most full time resources will be available 100% of their estimated/average capacity [never use peak or minimum] except when in vacation or absent. Vacations can be modeled as a buffer or as a calendar exception. If vacations are random it can become very complicated, if all employees use same vacations days the calendar exception is the way to go. At home it is common to assign a Xmas vacation period for most jobs. If your software is P6 or MSP that cannot model variable quantity on resource assignments and the impact on production rate and activity duration then better use buffer approach.
These are basic principles used by several known methodologies that use buffer management approach such as Project Risk Analysis [PRA] and Critical Chain Project Management [CCPM].
I have a preference on Project Risk Analysis methods as it does not depend on buffer as a task, while CCPM model buffers as a task and assume feeding buffers are static, which is not true in most cases. Also CCPM does not provide a rational way to determine buffer amount while PRA do.
https://tensix.com/2015/09/schedule-time-buffers/