Rafael Says Let’s Challenge Mike.

Hi Anoon

Very few UK Contractors have directly employed labour these days - all use sub-contractors or labour supply agencies where the pool is infinite.

The actual labour restraint is how many guys can you actually fit into the project - If you have welfare facilities for 100 each shift then you cannot fit 120 onto the site.

So having put the resources onto the programme (hours work balanced by efficient gang size) then the labour histogram is drawn on the screen which shows when the labour pool on site is likely to exceed 100.

In the columns I set up the gang size and the float.

Where there is float the gang size can be reduced or the FS sequence can be changed until all labour is below 100.

This would not be as efficient as the original but it will be workable.

I would never trust the software to do any resource levelling.

There are circumstances where specialist labour is in limited supply and a maximum deployment then has to be planned in from the beginning.

Best regards

Mike Testro

Mike

Some of our specs specifically prohibit the use of “soft logic” of any kind; maybe they consider it a float suppression technique. In such cases you have no other option than to use resource leveling or keep a separate schedule to manage your work.

What really surprises me is that they force you to use resource leveling within outdated and rubbish software as Primavera or Asta PowerProject, software without the functionality to show true critical path under limited resource constraining (resource leveling).

If you are not to be allowed to use “soft logic” then only Spider Project should be specified, is the only software I know that can show you true critical path under resource leveling. If you are allowed to use "soft logic" then Asta PowerProjet is a better option to Primavera products as it provides you to categorize relationships and in this way you can easily distinguish "soft" from "hard" logic.

I understand there is some incompatibility with combining the use of “soft logic” and resource leveling, but the contractor should be allowed to choose his own preference. I accept that because of the heuristic nature of resource leveling algorithms these will not necessarily always yield the optimum solution, “soft logic” also will not. There is no such thing as a perfect plan.

I am against specifications that prohibit the use of “soft logic”, it is your plan, as long as it is reasonable you should be allowed to present it and use it.

Best regards,
Rafael

Hi Rafael,

Sorry Mike, I made a mistake, I mean I’m 50% with you and 50% with Rafael (as long as he’ll bet in favor of Pacqiao).

By the way, what do you mean by "soft logic" and "hard logic"? is there a medium logic as well?

I supposed nobody understands this soft or hard logics in the field, can you present your schedule to your management and say, oh! in this case, I use 50% soft logic and 25% each for both medium and hard logics?

Rafael, think again please!???

cheers!

Hi Rafael

I only ever use FS0 links - what is soft about that?

Best regards

Mike Testro

Mike,

If you have 3 activities that you can work in parallel with no physical restriction to prevent it but you have a limit on resources, say the same crew to be assigned to the 3 activities, then the use of “soft logic” using “SF0 soft relationships” will solve the issue.

Because any of the three can be worked in tandem, on the sequence of your choice, the FS0 relationship is very soft indeed. SF0 can be as soft as you want it to be; usually the soft logic ties are FS0 links.

There is a misconception that soft logic refers only to resources, it can be space, safety, even culture (don’t ask me about culture I just read it somewhere).

Just Google for “scheduling soft logic” and try other key words such as “basics of cpm scheduling”.

Best regards,
Rafael

Hi Rafael

I often have trades - say plasterers - working down the floor levels and it would be economical to deploy two gangs who leapfrog each other down the building.

I Put in a FS0 link between "even nr" floor plastering and another for "odd nr" floor plastering gangs.

If that is Soft Logic then I have been using it for years and nobody ever told me before - I think I may have invented it.

To me the logic is just logic - nothing to do with hard soft or semi-floppy.

Best regards

Mike Testro

Mike,

What happens when you do not have floor no 13? A lot of frogs!

Anoon

Anon now you are 50%/50% you still have time to get on my side 100%. About Cotto and Pacquiau let’s hope it will be a great fight and not like many that end up being a disappointment, I hope both can give us a good Sabong.

Best regards,
Rafael

Hi Anoon,
of course we start with determining WBS and activities, and yes, we define the volumes (quantities) of work that shall be done on each activity. I don’t understand what did you mean by quantifying resources or crews. But assigning resources we define their productivities (volume of work that can be done in one hour). Basing on this activity durations are calculated during scheduling. Resources also have costs, may consume materials and all this shall be set.

The answer to your third question shall be calculated. It is easy to play what if scenarios and to compare project costs in both cases. If standby is profitable then select standby, if not – recall the crew.

Best Regards,
Vladimir

Hi Rafael

Now that we have entered into the realm of the frivolous a little query from the 1990’s it may not be releavent today.

What is the difference between a woman and a computer?

A computer will take in a 3 1/4 inch floppy.

Best regards

Mike Testro

Vladimir

What about space limitations when scheduling your activities, this cannot be modeled with the resource allocation functionality within our software? This got to be very relevant in offshore work similar to the shipyards.

Hit them hard, I still have the hope that eventually they will get it, even if by brute force, by repetition. Then they will ask for software with such functionality.

Mike,

LOL and a few more LOLs, thanks, some fun is always welcomed.

As you most probably noticed some of us do what you do with regard of resource leveling. It has worked fine for me but I wonder how difficult it got to be in large jobs when you get falling behind and got to release a multitude of the soft relationships, even when in time most probably the changing nature of resource relationships can make the resource leveling algorithms more efficient. To be able to compare both on the spot would be good. Under these circumstances, when using resource leveling, resource critical path is a must have otherwise is crazy.

Best regards,
Rafael

Hi Rafael,
Spider Project has many advanced features and we discussed only very small part of them. Yes, Spider Project can schedule projects taking into account resource, supply, financing and space limitations. It includes skill scheduling, it simulates working in shifts, it includes variable resource assignments, it works with activity physical volumes of work, it permits to create and to use corporate databases of different norms, it keeps project archives and produces trend analysis, and many other features that you will not find in other software packages.
Actually I don’t know Spider limitations. We can open new thread Let’s challenge Spider. Maybe somebody will find something that Spider cannot do?
Best Regards,
Vladimir

Vladimir,

It can be a very interesting thread as it will not be limited to a single issue. I will throw my best punches at you; will even throw a kick but no low blows, only relevant functionality. Multiple activities in a single bar is kind of borderline to me but the linear projects report is not, it is at the side of relevant functionality.

Hope it will reveal our needs and frustrations with available software.

I got a few ideas on where to get you. Don’t worry yet, true resource smoothing is something we do not use in construction jobs, I will not ask for it. I am curious about financial constraints, kind of novel to me, not to mention into multi constraint analysis.

Genetic Algorithms to tackle multi constraint optimization to me sound like science fiction, but I don’t care, just give me the functionality.

Mike,

You can hold him while I beat him; I just promised no low blows but mentioned nothing about holding him.

Best regards,
Rafael

Hi Rafael

I suppose Spider can use the Web better.

Best regards

Mike Testro

I really dont know what is going on here.

The thread start with raffy challenging mike

then how come

raffy want mike to help him beat up vladimir.

something wrong with raffy involvement in the pacquaia vs cotto bout

so strange this plannet.

Planning planet.

Thank you,
Scarlett

Hi Scarllet

Thats the way we like it.

Best regards

Mike Testro

Hi Vlad,

I refer to your post # 59 and if that his how Spider works ("activity durations are calculated during scheduling"), then I would say that I’ve never done like that (if there’s any schedule that I’ve made).

I presumed that you mean calculations of "original duration" and not remaining duration?

For me, if there’s an existing resource pool (maintained by a certain company for example), then maybe there is an existing "standard productivity rates" as well.

Now, if you had defined your activity or activities in a measurable manner, i.e. with measurable units, like m3; m2; lm; etc., I supposed you can also derive your resources or crew based from the existing "resource pool and rates" and from the activities that you had defined. This is what I meant for quantifying resources or crew.

I supposed as well that at first, you will always assign the average number (and never total or peak). So what’s the main reason of leveling resources when you had already known the average number (and that is supposed to be your budget)?

I also believed that your last paragraph (post # 59) answers the question.

"Resource Leveling" only boils down to "Profit Evaluation"


Rafael,

I never expected that you knew "sabong" as well. Well, maybe because your ancestors brought it to us. Don’t tell us that you’re also playing that? No wonder why you are well versed in "contracts".

cheers!

Hi Anoon. in Spider Project we define the volumes of work to be done on activities, we define standard productivity rates (Spider Project creates reference-books for all norms), we define crews that are used on activities of different types (also may be standardised in the reference-books), we can also define skills when different resources may do the same work (though maybe with different productivities). Then crews and roles are assigned and resource constrained schedule is calculated. If you are not happy with the results you can change some crews (adding or replacing some resources as an example) and recalculate the schedule until you are satisfied. The good thing that you can change the crew in one place (in the crews table) and everywhere where it used the crew will be new. It makes what if calculations easy to do. And I mean recalculation of remaining durations because the volumes of remaining work may be changed. If you assigned skills you don’t know what resources will be assigned before scheduling. Most productive resources may be busy on other activities or have vacations and Spider Project will assign those who are ready to work. In this case preliminary calculation of activity durations is useless. Please clarify your question if I did not answer. Best Regards, Vladimir

Vladimir,

I don’t really believe that I can absorb what you are trying to say. I supposed my role here is just to hold you and let Mike and Rafael beat you up! Or is it Mike to be beaten up?

If what you are saying with "Spider" is true (considering that I’ve never seen or used it), I supposed your software will make the Planner the laziest worker in this world!

Or maybe it can get rid of the Planner’s or Quantity Surveyor’s jobs (I don’t want to use it of course).

As I understand from what you had said:

1. Different Skills - Defined and categorized with different productivity rates.

2. Crew - Composed of different Skills (Tailored for a specific activity)

3. Roles - Maybe with Skills and Names (I’m not sure)

4. Materials - I don’t know how you’ll define it?

All of the above are stored in a pool or a dictionary, and once you had laid out your activities, you’ll just pick from the pool the appropriate resource or crew and assign it to an activity or activities.

From there, the program will calculate durations for you? (considering that you just leave the original duration blank?).

And it will level resources as well considering that maybe some are in vacation?

Now, Mike and Rafael - all you are saying are obsolete!

cheers!

Hi Anoon

Powerproject can do all of that if you want to use it.

I use resource modelling when I am dealing with delay or disruption claims and to calculate the effect of acceleration.

I try to keep things simple by:

1. Using only 1 permanent resource - Hours - extracted from the cost plan.
2. Assign the task calendar to the resource - 1 tick box and it is automatic.

And that is it.

Best regards

Mike Testro

Anoon,

Here we are supposed to beat Mike, the original issue was about use of lag and relationship types. Mike is a proponent of FS0 only, he means Finish to Start, zero lag relationships only. In order to do that he proposes a methodology he calls Bottom up. Our argument is that this cannot mimic true laddering with continuous feed and here Vladimir is very knowledgeable as Primavera product does not have this functionality. In order to Bottom-up your activities Mike methodology creates so many extra activities that make it unpractical. We also argue the validity as this is not equivalent to the use of lag.

My claim is that when you have continuous feed relationships you need SS an FF with equal lag between your activities, and that this is a genuine use of SS, FF and lag relationships. I also maintain that there are also other uses for this and the remaining types of relationships other than FS, these are SS, FS and FF with lag, being FS the least used or justified. I also recognize there are traps in the use of these but the lack of care or of knowledge for not falling into these traps do not justify the banning of these useful relationships.

Vladimir agrees that these relationships are useful and mentions the functionality of continuous fed relationships (he uses another term) that creates laddering with some additional functionality you cannot get by the mere combination of these relationships, he is correct.

Finally it came out the issue on resource leveling. When you do resource leveling the software loses track of true critical path and resource float. In this regard the only software that provides this functionality is Spider Project.

My people believe that losing track of your true critical path justifies the use of “soft relationships” and we have used this methodology with success because of the relative small size of our jobs (~400 to 600 activities). In the lack of this functionality we use an approach similar to Mikes. I believe this methodology would not be as easy to apply in jobs with thousands of activities as in order to “unlevel” the schedule and get your new “soft relationships” when compressing the schedule makes it a monumental task.

Lately I have been amazed at the functionality Spider Project provides, some are difficult to realize and understand as our software is lacking many of these. So let beat Vladimir to explore these additional functionalities.

Best regards,
Rafael

Anoon, beat Mike in this thread and beat me and Spider in another http://www.planningplanet.com/forum/forum_post.asp?fid=1&Cat=1&Top=65251 You are almost right describing the way of work with Spider Project. Actually you need to do the following: 1) Create project WBS (you can also use templates), 2) Look at the Fragment Library and find there small projects that model your work packages (with some standard volumes of work), 3) Replace your work packages by these fragments in your schedule. During the replacement specify your real volumes and Spider will adjust fragments in your schedule, 4) For those work packages that do not have analogues in your Library create activities, link them and specify activity types and volumes of work, 5) Apply reference books. Resources (crews, skills) will be assigned, productivities will be defined, material requirements will be defined, costs will be defined, 6) If some activities are of the new types you shall enter the information manually but don’t forget to include it in the Reference-books for future projects. 7) Link activities of different fragments (work packages) with each other (internal links are already there), 8) Enter external constraints (start no earlier than, financing schedule, supply schedule, etc.), 9) Calculate resource constrained schedule and the budget and study results. If you are unhappy with the resource constrained schedule calculate the schedule without resource constraints and look at the activities that were delayed. You will also know the total delay and the best possible finish date with your resource assignments. 10) If the best finish date is still not satisfactory increase the number of resources in the crews that are assigned on critical activities. It can be done if you will just change the numbers in crew definitions. Recalculate your schedule and compare results. If scheduled date is satisfactory and levelled date not consider the options of using additional resources or different work calendars. 11) Look at the Resource Gantt Chart and find resources that are most busy. You will also see critical assignments - those who have no floats, or small float (you can specify the quantities). Decide if the number of these resources may be increased. Play what if until you will find a solution or suggest the best possible finish date with your resource restrictions. We did not discuss risks but still project planner has a lot of work to do. Using Spider he will skip routine work and will be able to play a lot of different scenarios. Please ask future questions on Spider in the other track. Hi Rafael, I will study your references before answering your questions in Spider track. Best Regards, Vladimir

Anoon

Mike is into nano-management, he is even a step ahead of micro-management. He does not believe you should be allowed to manage your jobs at your management style but only at his, he feels the urge to ban what does not fit his style.

As you can see I promote to allow more options than to ban them for convenience. Let the contractor’s decide if they want to go with manual leveling or computer aided leveling, both have their place into management.

New functionalities open your options, freedom is about options, don’t become a micro-manager. Empower all in your enterprise, don’t use the tools to steal away middle management authority while keeping responsibility on them, is absurd, you might be creating Micromanagement Zombies.



Many higher learning institutions are developing computer algorithms to solve real life constraints, this mean multiple sets of constraints at the same time, let’s challenge them to include these into our software. Traditional CPM is kind of outdated, Spider Project is taking the lead, no doubt about it.

Best regards,
Rafael

Hi Rafael

My position is that if there is an error in fixing rebar on bay 5 level 4 I have to know precisely where that task sits in my programme so that I can impact the delay with pinpoint accuracy.

This goes for live projects as well as forensic delay works.

Also I prefer to set up systems that I can both control manually and understand.

I am now locking this thread because it has not attracted many PP members.

Send me a PP message if you want to continue with it.

Best regards

Mike Testro