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Advise/help on MSP 2007

6 replies [Last post]
Maarten van Wyk
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Joined: 9 Sep 2010
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Hey Guys,

I have a few questions on scheduling of activities in MSP 2007. Any help/advise will be much appreciated.

I have an activity that if it is 50% complete, a successor will start. How do I link them or do I have to break up the predecessor activity into two activities?

Can I apply different working times to different activities/areas? eg. mining resources are working 3 x 8hour shifts but the construction resources work 1 x 8 hour shift per day, both schedules are integrated into one schedule due to activities affecting each other.

How can I measure my resource productivity? We are working on a monthly bonus scheme and we want to deduct the % of work not completed from their bonusses.

Your help will be much appreciated.

Maarten

Replies

Rafael Davila
User offline. Last seen 8 hours 21 min ago. Offline
Joined: 1 Mar 2004
Posts: 5229

Try assigning a 24/7 calendar to your activity while for each resource assign its own calendar.

attempt to model shifts

Then try shift work with activity duration driven by resource production.

Regards,

Rafael

Maarten van Wyk
User offline. Last seen 12 years 43 weeks ago. Offline
Joined: 9 Sep 2010
Posts: 7
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Thank you very much for the inputs. I appreciate the help. I believe the best bet would be to divide/split the task in two separate tasks and link the tasks accordingly.

 

With regards to the calendar, if I set up a new calender for morning shift and I change the working hours to 04:00 - 12:00 and I create another calender for afternoon shift from 12:00 - 20:00 and another for night shifts from 20:00 - 04:00, and I apply the calender to the resources in the schedule, MS Project keep setting the working hours to the previous setting and make all three shifts 12:00 - 20:00, which defeat the purpose. Any further advice? Should I change the workday to 24 hours maybe?

 

Regards,

Maarten

Maarten van Wyk
User offline. Last seen 12 years 43 weeks ago. Offline
Joined: 9 Sep 2010
Posts: 7
Groups: None

Thank you very much for the inputs. I appreciate the help. I believe the best bet would be to divide/split the task in two separate tasks and link the tasks accordingly.

 

With regards to the calendar, if I set up a new calender for morning shift and I change the working hours to 04:00 - 12:00 and I create another calender for afternoon shift from 12:00 - 20:00 and another for night shifts from 20:00 - 04:00, and I apply the calender to the resources in the schedule, MS Project keep setting the working hours to the previous setting and make all three shifts 12:00 - 20:00, which defeat the purpose. Any further advice? Should I change the workday to 24 hours maybe?

 

Regards,

Maarten

Rafael Davila
User offline. Last seen 8 hours 21 min ago. Offline
Joined: 1 Mar 2004
Posts: 5229

Maarten,

Be careful about activity splitting, it changes the model, can yield unexpected results if for some reason such as resource leveling or if logic links separate the start of the second activity from the finish of the first. Even if your software is capable of correctly model shift work, activity splitting can yield undesired results. Look at the following print screen and you will see one of many possibilities.

Activity Splitting ...

If you rented a tunneling machine to perform the Activity now you have a gap between the two halves and the equipment might be idle for a substantial amount of time.

Usually most activities shall be scheduled under continuous PDM, non-continuous PDM across the board is wrong. No short cuts here, do your homework and decide when to split and how on a one by one basis. Yes, at times activity splitting resolve issues on resource availability, learn to deal with it.

From: Scheduling 101: A "Behind-the-Scenes" Look at Basic Schedule Calculations

http://www.pmicos.org/topics/aug2006tom.pdf

-“If the project duration is the same with either method, then use PDM with continuous durations to avoid the possible complications (productivity losses, quality, cost, etc) that are caused by PDM with interruptible durations. However, if the PDM with continuous durations results in a longer project duration, then further analysis is warranted. First, perform a schedule analysis to see which schedule activities need to have interruptible durations to shorten the project. Careful analysis of both the schedule and cost impacts on the project allows the scheduler to choose whether to use PDM with interruptible durations or PDM with continuous durations (Orczyk and Jenkins, 1999)”.

Say on a concrete pour after 30% done you start moving screeds (another activity), after 45% you start hand finish edges (another activity), after 50% you start machine troweling (another activity), after 80 % you start placing curing compound (another activity). How are you going to split it if in need to see the sequence? If you do not need to see the sequence, maybe a single activity per job will do it. What if you need to use personnel efficiently or perhaps the other personnel will be watching the pour having a few beers until it is time for them to star working. I solve it quite easily without splitting the activity by using partial assignments but MS Project do not provide for partial assignments. Use of lag is needed to overlap activities when in need to keep them continuous and many times to get a better resource distribution. We have two types of lag, duration lag and volume lag; they do differ and yield correct modeling. Consider the use of lag, even if you only have duration lag.

Regards,

Rafael

Rafael Davila
User offline. Last seen 8 hours 21 min ago. Offline
Joined: 1 Mar 2004
Posts: 5229

Maarten,

Beware that some software cannot correctly model shift work when the duration of the activity is driven by how much work is produced by the resources on different shifts. I understand neither MS Project nor P6 can deal with this issue unless new versions were updated to correctly model shift work.

You can try yourself a simple scenario.

Activity 1

500cm rock excavation

Resource 1 production 10cm/hr  and works Monday, Tuesday and Wednesday 10hrs/day

Resource 2 production 15cm/hour and works on Wednesday, Thursday and Friday 10 hrs/day

If activity starts on Monday:

Monday =>> Resource 1 will produce 100 cm

Tuesday =>> Resource 1 will produce 100 cm

Wednesday =>> Resource 1 will produce 100 cm

Wednesday =>> Resource 2 will produce 150 cm

Thursday =>> Resource 2 will produce 50 cm in about 3 hours

Activity will take 3 days 3 hours.

If activity starts on Wednesday :

Wednesday =>> Resource 1 will produce 100 cm

Wednesday =>> Resource 2 will produce 150 cm

Thursday =>> Resource 2 will produce 150 cm

Friday =>> Resource 2 will produce 100 cm in about 7 hours

Activity will take 2 days 7 hours.

If your software is not capable of modeling the above, simple shift work on a single activity, then you are using the wrong tool. Every time the activity is delayed the distribution of work is shifted, when you have many such activities and work on different hour shifts, different days it can become quite complicated. Distributing work by hand is nuts.

LOL AND LOL

Regards,

Rafael

Trevor Rabey
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Joined: 29 Nov 2005
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Yes, you need to break up the task into two tasks and the first is the predecessor of the second and also a predecessor of the following task.

Yes, you can make 3 calendars for the 3 shifts and anoither for the regular hours guys. Then you have to amke sure that those calendars are assigned to the applicable resources (not the tasks).

I could help with the last question if I could see the file and if I knew the details of the arrangement.