Machine and worker schedules in MS Project

[pedrosantos]

Hi!!!
I'm starting to build some projects using MS Project and I'm facing some issues.
The projects I'm building have several subprojects embedded and they all share resources (machines and workers). Although machines are workers dependent, I need to use both resources in order to avoid both machines overallocation and having more workers working than those that I have available in reality.
Workers can be grouped according to their schedules, and I'm representing each group of workers by a single resource that has a maximum units equal to the number of workers in the group.

At the present time, I'm using different base calendars to each group of workers and the 24H calendar to the machines. However, I have faced the following issues:
1 - Imagine a task the begins at 11am and workers have to do 4hrs of work. If they stop at 12am for an one hour lunch, the task will end at 4pm, having 5hrs of duration. However, due to the 24h calendar, the machine will end at 3pm, being wrongly available to other tasks between 3pm and 4pm. To overcome this issue I'm using a task calendar which is the same used for the workers, forcing the machine to stop working between 12am and 1pm. Although this solves the problem, as the number of projects increases and with the levelling pushing tasks to hours for which the used workers resources have to be changed with others that in fact can do work at that time, I believe that I will end up spending more time changing calendars than analysing the overall project plan.
2 - Since they are all different base calendars, if I add any exception to the project's calendar it will not be reflected in the resources calendars.


Could you please guide me to best way of dealing with different schedules?? Should I create different base calendars to each group and use them as resource calendar?? Or should I use just one base calendar (project's calendar) and edit it for each resource according to their schedules??

 

[johnherman]

You can assign a calendar to each machine (and each worker if necessary). In fact, I recommend one calendar per machine because it helps with tracking scheduled and unscheduled maintenance. So, to answer your question, I think the better solution is resource calendars within the project(s).

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The trouble with doing something right the first time is that nobody appreciates how difficult it was - Steven Wright

 

[SkipVought]

Hi,

First, I am not a Project expert. I can barely spell it.

However, I work as a Resource Analyst in a large machine shop that makes gear boxes for aircraft. Actually I support the RA's as a programmer analyst with software tools to make them more efficient.

We deal with machine capacity often, although the industrial engineers share that issuer with the RA's. The IE's look at overall capacity issues, while the RA's are concerned with the capacity as it relates to the schedule of orders that are to be worked in the future. So as far as the MRP system is concerned, machine capacity is infinite (in other words, MRP does not consider capacity). I think that's true of many scheduling systems. The LOAD is obtained from the standard hours in the order schedule, and when a simulation of the schedule is run, the load on Amy machine can be compared to the capacity profile.

So what is a capacity profile on a machine? Often one employee runs one machine. That is not always the case, as an employee could run more than one machine. But how that is mapped to the scheduling system is vital. Tharp are issues like the type of machine. Let's say you have machine groups that are cutters, shapers and processors. The cutters (some or all) can be run by a computer. Does the guy need to be at the machine while it's cutting chips? The shapes only produce while an operator is feeding material and engaging the machine. The processors are batch type machines where material is prepared, inserted into the machine for a shift+ period of time. The operator is off doing other things.

So the answer to your question really requires a lot more information about the individual machine. A machine is sitting there for 24/7, but it is doubtful that it is AVAILABLE for productive work 24/7. In the example you posted the machine is only available for productive work when an operator is at the machine. So THAT machine is tightly coupled to the employee calendar FOR PRODUCTIVE WORK, while there may be other hours for that machine thar are otherwise available (perhaps for maintenance, training, tape proofing etc)

So now a Project guru needs to address the calendar issues. I just threw up some possible issues to consider.

Skip,

_{Just traded in my OLD subtlety...
for a NUance!}

 

[pedrosantos]

Thanks for your help.
In fact machine only do work when operated by a worker. However I have different groups of workers, each with its own calendar, that can operate the same machine. To cope with this, I use a 24H calendar for the machines in order to always have a common calendar period that matches the worker calendar. I don't know if this is the best solution or if Project has a built in solution to automatically define a resource calendar according to a given condition. If one would exist I would be very happy to know.