Let’s Challenge SPIDER
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I proposed to suggest hard tasks, something that most or all packages cannot do. I will answer if and how it can be done in Spider.
For those who did not hear about Spider Project - this is Russian professional PM software. At the moment it is used in 26 countries.
So this thread is for questions on functionality that is useful but is not supported by the packages that you use.
Rafael Davila hopes that other software developers will look at this discussion and then will make their packages more functional.
I will start with answering to his question on project scheduling with financial constraints.
Sometimes when you start the project you have not all necessary money. You may know when and how much money will come to the peoject (financing schedule). If financing schedule is a part of your project schedule model then Spider Project will calculate project schedule taking into account financial limitations and delaying activities when there are no money to proceed.
Actually it is even more complex - some activities may generate money (selling flats in the building in the process of construction for an example), that may be used for financing other activities.
All this can be simulated and an example of the project with financial constraints is included in the Spider Demo.
I am waiting for your questions and hope for fruitful discussion on PM software functionality.
Best Regards,
Vladimir
381 replies
Oldest first- 0Augustin Purnus ·Rafael,
The Reference Books will transfer data. If it is empty than you will transfer “nothing”.
It is easier to simply go to the Links Table, select all links and delete them. Then, transfer the new links. You can create different links in different tables and transfer them into the project. To keep the scenarios, save as with different version numbers.
I was just playing with Switch type of activity and Switch Condition for the links. It shows similar with the decision tree (if, than, else). I had last year a project where the client wanted to see different activity sequences based on a decision point, like Switch. I didn’t have at that moment such feature, but I’m happy it is available now. However, I look forward for the improvements Vladimir told.
Except Pertmaster and probably Open Plan which apply Monte Carlo and Conditional Branches, I don’t know other solutions with such a feature.
Best regards,
Augustin
- 0Rafael Davila ·Augustin,
The data transfer default might be to transfer to existing rows only but you have the option to create new rows as well as full transfer. I was thinking in an option to delete matching rows. In this way you can apply your deletions to any previously updated version as well as to restore it back without the need to create additional versions and without the need for additional backups; your backup is the Reference Book per se unless you want to back it up also.
Also if you want to undo it would be a single or a few protocol of actions lines.
Remember we all have our particular needs and ways of doing things, keep sharing yours, we all need other point of views.
Best regards,
Rafael - 0Augustin Purnus ·Hi Rafael,
You are right. I explained only what can be done now.
You are talking about a new feature which requires some developments. I don’t know what means from this point of view, what effort should require, but thinking “out of the box” is the best way problems can be solved.
What I really love at Spider Project Team is that if there is a new feature required by the users which improved the solution, than they will do it very quickly.
Best regards,
Augustin
- 0Vladimir Liberzon ·Hi Rafael and Augustin,
yes, reference-books can be used as backups.
An example:
You created reference-book of the project hard dependencies.
Then you added soft dependencies.
Then you decided to delete all soft dependencies and restore the initial network logic.
For this you shall open Links table, select and delete all links, then open reference-book with the stored links and transfer all of them to the project.
Best Regards,
Vladimir - 0Rafael Davila ·Augustin
Spider Project structure, screens, functionalities... are so well designed that will allow the developer to improve on it for many years to come in ways a few others will be able.
If I used Primavera SureTrak for 10 years and it was never improved, most probably I will use Spider for twice these years.
Vladimir,
If good for 3,200 additions then why not also good for 3,200 deletions.
If I want to apply the deletions of say 20 links to 8 versions, for forensics, it would be 160 deletions, if I want to apply it to 20 different schedules that used the same logic, also to 8 versions of each it would be 20x20x8 = 3,200 deletions.
Best Regards,
Rafael - 0Vladimir Liberzon ·Hi Rafael,
though this is rarely required it is easy to add new option to others.
So they will include:
1) Modify existing objects,
2) Modify existing and Add new objects, and new
3) Replace all objects.
Did I understand your proposal properly?
In my previous post I explained how it can be done at the moment.
Best Regards,
Vladimir - 0Rafael Davila ·Vladimir,
Probably I would say add the following transfer Method: "Delete matching rows" to the Data Transfer Setup dialog box. By matching I mean matching key field only.
With all the existing options for "Transfer to" and "What to transfer". As to have same control on these two options. Maybe "Column type" dimmed when selecting this new option, not sure about Data Transfer Options buton.
The basic idea is not only being able to add rows but also to delete multiple rows and then by clicking on any other option for "Transfer method" you can get them back using the same Reference Book.
I understood your proposal and believe that what can be done at the moment is far superior to what can be done with other software. It is just that Reference Books seems so logic it is not difficult to imagine using these to systematically delete table rows (in the hundreds), to use them to repeat the deletion in other schedule update versions and to use them to restore the deletions without missing a single deletion and restore.
Best regards,
Rafael - 0Rafael Davila ·Vladimir,
By creating a custom field and a formula I can reassign ID codes to my activities with ease but reading about Reference Books I crossed with the statement that it is also possible to transfer data to a key field in addition to transfer fields. I used Reference Books as another way to change my activity ID’s, a key field, and it worked, this will make it easier to change activities ID’s in all my versions or prior updates.
By the way on purpose I duplicated some values and did not transferred duplicates, some day I will find a way to corrupt the database using Reference Books. Perhaps if you add the functionality to delete records using Reference Books the banana peel will work, like Wile E Coyote I will keep trying.
Best regards,
Rafael - 0Vladimir Liberzon ·Hi Rafael,
if you will corrupt the database using reference-books it will be very useful for Spider improvement. Thank you for trying and inform me if you will find the way to do it.
The reference-books can be used for anything like creating the dictionary of activity and resource names that can be used for automatic creation of many languages project model (English, Spanish, Russian, etc.).
I will discuss deleting option with our programmers when will return to Russia.
Best Regards,
Vladimir - 0Scarllet Pimpernel ·Good Day to all,
I did read this tread and got lost along the way. With 300++ post and 4,500++ viewers, whats now?? How will it benifit me or the common planner?
to shoot down Primavera, I seems to agree with one post that Primavera indeed was highjack by IT. Primavera started as a construction project management software and end as an IT project management software. It should not be a surprise knowing Oracel bought Primavera.
So, there is no point in criying against Primavera, it will just die a natural death, irrelevant to construction project management.
I would also say, forget Microsoft Project for idiots.
But there is new hope because we have Spider as a project management software.
My question to Vladimir: what is your strategic plan to make Spider the software of choice for construction project management professional?
Thank you,
Scarlett - 0Raphael M. Dua ·Scarlett P
What a narrow view of the world of Project Management software you have
If you visit the Planning Engineers site www.planningengineers.org and go to the survey tab, you will see a large number of software packages.
My own software Micro Planning X-Pert for Windows and Mac happily keeps selling to all industries and I must admit I have seen in recent times an upsurge in small to medium sized builders buying my product, especially as they now seem to be moving towards earned value and of course resource scheduling.
I would suspect that more than 80% of users do not want the complications of SPIDER, P5 OPP, Astra Power PERT
My client base justwants to plan and schedule quickly inexpensively and get the best results with the need for a vast SQL and DB infrastructure
Rafael
Frankly I think it is time to stop this non stop let’s Challenge Spider and get on with some work for your client
The challenge for our limited time now is to provide some help to Haiti and help them rebuild and do something practical.
I am looking at trying to offer the UN some Planners and Schedulers using our skills to help the people on the ground, as we did for WHO the 2004 Tsunami in Indonesia and Asia
Raphael - 0Vladimir Liberzon ·Hi Scarlett,
Spider Project is already the software of choice for construction project management in Russia and is used by most Russian construction companies. It is also used by large corporations involved in construction of plants, dams, and other facilities. But it is also used in other industries including IT.
We know that any project management software is a tool that shall help in managing projects. Without proper project management system the software will be used for drawing charts and in this case Spider Project advantages are useless. So we help to implement not just Spider but project management systems for our customers. Our company is involved not only in the software development and customers support, but also in consulting, training and project management. We manage construction projects for our customers and thus have very good understanding of construction management needs.
But we do not believe in advertisements. We never marketed Spider Project. Our promotion – happy customers who told others about their satisfaction. In any case we are not able to compete with Oracle in software promotion and we do not want to sell the software to incompetent buyers, who will use it for drawing.
We have branches in other countries with very competent managers. They use the same approach. It works but it is a slow way. We have customers in 27 countries and many of them found Spider Project in the Internet. They used other softwares but understood Spider Project advantages. Our potential customers are those who want better planning, shorter schedules, resource usage optimization. It is a minority but we are interested to work with this minority. We are afraid just to sell the software, it is dangerous for Spider Project reputation.
So we have no strategic plan for Spider Project promotion, we just make it better and better each month and hear customers needs. I’ll be grateful for your ideas.
Thank you and Best Regards,
Vladimir - 0Scarllet Pimpernel ·Dear Raffy D,
Please do not impose to Raffy what to do and what not to do.
Raffy Davila did a good work by helping the PP community understand Spider Project Management better than before. No other PP member have ever done what Raffy did here. And it did give the PP community a hope that somewhere there is a better construction project management software than Primavera P6.
If you really feel that your software is the best ever, you can always plead for your case here in PP.
Remember the tenets in PP is Freedom. and through freedom only mankind can achieve the best ever.
Thank you,
Scarlett - 0Rafael Davila ·Vladimir,
Thanks you for your briefing on the application of fragments.
…”For repeating sets of activities we suggest to use the typical fragments library that consists of small projects that model typical sets of works. You can use insert other projects as the new phases. This is the way we use working with the fragments. The software asks what to do with activity codes and volumes. Activities may be scalable or not (look at activity properties). If scalable then their volumes, durations, etc. will be multiplied by the user defined number”.
I noted that even resources definition is transferred so if new resources are required these will also be transferred.
This feature of being able to scale the fragments is something I have never seen before. With Primavera SureTrak I did not even had the basic functionalities of fragments. Do you know if such “scalable” and transfer of resource definitions are features available in other software?
Best regards,
Rafael - 0Vladimir Liberzon ·Rafael,
I don’t know software packages that have similar functions.
This is the way we create complex project models.
Fragments describe typical work packages for certain work quantity (1km, 10m3, etc.). Inserting the fragment project planner defines the real volume of work at the certain work package and fragment data will be adjusted automatically.
With fragment library it is easy to create large project models:
Project Planner creates WBS, then inserts project fragments at work packages level, then creates links between activities of different work packages. Everything else is already there - resources, costs, calendars.
Fragment Library is the main element of the corporate PM system.
Best Regards,
Vladimir - 0Rafael Davila ·Vladimir,
You got it very right; my question was about scalability and transfer of resource definitions.
The great thing about it is that scaling is defined at the activity level so when scaling your fragments only scalable activities will be scaled. If you have a fragment for mat foundations, you would transfer several activities whose duration will depend on the scale but others will not be changed such as concrete curing.
Maybe you cannot say all activities will either be fully scalable or not scalable, a few will fall in between. I would dare to say over 95% will be covered and the remaining with a simple adjustment can be handled. Hey you are transferring even resource definitions.
Please don’t complicate fragments, keep is as simple as it is, cannot get any better.
Best regards,
Rafael - 0Safak Vural ·Dear Mr.Liberzon and Mr.Davilla,
First of all I want to congratulate you for the battle you continue to make people hear you. I wish you to continue your way and conquer more castles in project controls territory.
I am trying to follow this thread with playing in your demo. Everything seems so perfect user friendly and solution oriented in software. Personally ASTA – Power Project seems good scheduling software also. But the ORACLE® and PRIMAVERA® are offering some other aspects as well. Also all my clients are commitetd to them. In many projects I touch or hear (from colleagues etc.) cost control - oracle rdb, estimating and quantity surveying sql rdb, HR and personnel time recording oracle and sql rdb, QA/QC sql rdb ……. List can be longer. Data collecting is becoming easier and IT works is becoming user-friendly everyday. SPIDER® has to fight with these kinds of integrated packages in the market also due to availability of direct integration for PRIMAVERA® products with that kind of databases.
Can I challenge SPIDER® team not with software with studies, papers, procedures etc. If you check all major construction companies in OIL&GAS almost all their project control documentation based on duration based CPM where majority of them referencing PRIMAVERA® directly.
Can you provide more documents about projects which used SPIDER® and Critical Chain Project Management (Like Urucu-Manaus Gas Pipeline)? It is not easy to find papers, studies etc. supporting Critical Chain. Can you reference papers? Can you create a package that the Project Controls for Critical Chain approach with all main and support processes including inputs, outputs, responsible items, customers, where you can include SPIDER® in one or more of this processes. I checked all publications SPIDER® web page but I cannot find anything which is answering the questions above. If there are academic references you can provide I will be happy also. I will try to access them from my university library in my vacation times at my hometown.
Regards,
Safak Vural
- 0Rafael Davila ·Safak,
In Spider Project you can run Scripts from outside Spider so you can have access to all the power Reference Book provides. If your software can access text files then it can communicate with Spider Project, if I understood correctly what Vladimir once mentioned in one of his postings.
Perhaps it is not a good idea to have a direct link to the database fields as this can corrupt integrity of the data, Reference Books provides the link. Field relationships in CPM are not as simple as relationships within a database.
I do not have such a requirement in my jobs but Spider can provides for the most demanding requirements, on my part you are welcomed with your questions, I believe this kind of questions were missing and your postings will add value to the discussion.
If I am right maybe in a future we will be exchanging script templates to communicate with Oracle/Primavera/Microsoft/SAP/....
Best regards,
Rafael - 0Vladimir Liberzon ·Hi Safak,
I am sorry that there are few Spider papers and presentations in English. Don’t forget that it is Russian software. The documentation that is created by Russian corporations is in Russian and Brazilians publish their papers in Portuguese.
Spider site contains papers and presentations mostly made at different PMI events. At these presentations I talked about the methods that we use trying to avoid mentioning Spider. Spider Project was and is used for management of many oil&gas construction projects in Russia, Ukraine, Belarus. Examples; Caspian Pipeline, Blue Stream, Nord Stream, East Siberia – Pacific Ocean, and other pipelines, development of Bovanenkovo Gas Field.
Best Regards,
Vladimir
- 0Vladimir Liberzon ·Rashid,
if you will download Demo version of Spider Project from http://www.spiderproject.ru/demo_e.php you will find there sample project that includes construction part (a small part of the resl project), financing, and future profits.
In this project you will find multi-resources (crews) assigned to construction activities, activity durations that are calculated basing on their volumes of work and assigned resources productivities, cost components and cost centers, cash flows that includes expenses and financing, expenses and incomes that are calculated with cost discounting, materials that are assigned per work volume units, resources that work in shifts. In this project you can try cost and material levelling.
It is small part of many unique Spider Project features but you will not be able to repeat this project using other softwares including P6.
Spider Project optimizes resource constrained schedules. Recently Rafael uploaded small and simple project but P6 produced optimal schedule (the same as the schedule produced by Spider Project) only after manual assignment of activity priorities. Impossible in large projects. And in many real projects the difference of schedule durations is huge.
I can add skill scheduling, trend analysis, etc.
If you ask about some reports I suggest to look at Linear Diagram - it is Time-Location Chart that is one of many projectt reports.
If you want to see something specific please ask.
This thread was created for challenging Spider Project - I am still waiting for hard tasks. If you need something that other PM software does not do, ask if Spider Project can do it. Two options - I can explain how Spider does it, or you will suggest Spider Project improvement.
Best Regards,
Vladimir - 0Vladimir Liberzon ·Rafael,
for high rise buildings it is also very useful.
The metrics consists of floors (or levels like in your example) and Lnear Diagram shows what work at what floor will be done at what time.
But in any case it is just one of many reports that may be used along with the Gantt Charts.
Best Regards,
Vladimir - 0Rafael Davila ·Vladimir,
Yes, it is a useful visual report, but my point is that it shines in linear projects.
And while contrary to other linear diagram tools, in Spider all the PDM functionalities are also available. The PDM metrics matter as much or even more, still if a linear job, the Graph is just a representation.
Best Regards,
Rafael - 0George Mejtsky ·
Vladimir,I respect you, and I
Vladimir,
I respect you, and I agree with your postings. In fact, I cannot find even one sentence where I would not agree with you. You proposed to suggest hard tasks so I will try my luck. I am coming from production scheduling field, and I wonder whether your Spider Project software can solve some of shop scheduling problems. I will describe such problems by project scheduling terms.
I have several projects: The first project P1 starts with activity P1A1. The activity P1A1 requires resource R1 for p1a1r1 minutes, and then the next P1 activity A2 requires resource R2 for p1a2r2 minutes. The third activity A3 of P1 requires resource R3 for p1a3r3 minutes, etc. The second project P2 starts with activity P2A1 requiring resource R1 for p2a1r1 minutes, and then the next P2 activity A2 requires resource R2 for p2a2r2 minutes, etc. The third project P3 starts with activity P3A1 requiring resource R1 for p3a1r1, etc. So each project has a sequence of activities and each activity requires a resource for a fix time. Each resource Ri can be assigned to only one activity (resource capacity is 1). This is a resource allocation problem. The question is how to allocate each resource so that to minimize the overall completion time of all projects.
I guess Spider Project software can solve this type of problems. Can you tell me if and how it can be done in Spider?
Best Regards,
George
- 0Vladimir Liberzon ·
George,Spider Project is used
George,
Spider Project is used for production scheduling in Russia, Ukraine and Brazil. Recently I received a letter from Brazil where it was written that Spider is used for production scheduling instead of Preactor because Spider schedules are much shorter.
But Spider still does not model time necessary for changing the tools when there is a need to do different type of job. This is serious restriction if these times are large.
You described famous NP-complete problem and Spider does not guarantee the optimal solution but its iterative heuristics finds the solution that will be close to optimal. I added fourth project (machine) to the example below to show what Spider will do solving your task.
Mike, I am curious if Asta will produce the same (or better) schedule for the same problem out of the box (without applying user defined priorities). Please enter the same data into Asta and show us the result.
Regards,Vladimir
- 0Mike Testro ·
Hi Vladimir I did not see any
Hi Vladimir
I did not see any item about changing tools in Georges thread - just applying Resource R1 to a number of different tasks in different projects.
That is the same as allocating Crew 1 to different sections of a pipeline.
If there is to be a time required for tool change over then that could be done with a simple task set between changeover tasks or alternativel a lead time on the link if the calendars are compatible.
Best regards
Mike T.
- 0Vladimir Liberzon ·
Mike,I did not mean George
Mike,
I did not mean George example but general production scheduling.
If I don't know the next work then I don't know necessary tools and what time is necessary for tools adjustment. So I cannot add changeover activity because don't know what work will be next and what time will it take. It is not actual in project management but may be critical in production scheduling. I think that we will add this feature to Spider since we have more and more customers in manufacturing.
Did you try Asta with my example?
Best Regards,
Vladimir
- 0George Mejtsky ·
Hi Vladimir,Thank you for
Hi Vladimir,
Thank you for your detailed response and your time with the problem (4 projects and 3 resources). Why Spider schedules are much shorter than Preactor schedules? I am trying to find software which is better than others, producing shorter schedules than competitors can produce. I do not care about optimal schedules, I only care about just better schedules than others can produce. How do iterative heuristics of Spider find a good solution in this problem of yours?
Mike, thanks for participation in this discussion. Is your schedule shorter than 51 minutes?
Vladimir, can you try another problem with 6 projects and 6 resources? No tool change time (set-up time) is included, and each resource has capacity 1 (quantity 1). To describe the problem, I will use a short notation: resource number/duration. For example, 2/1 means the operation needs resource number 2 for 1 minute.
--------
Problem (6 projects, 6 resources):
P1: 2/1, 6/3, 1/6, 3/7, 5/3, 4/6.
P2: 1/8, 2/5, 4/10, 5/10, 6/10, 3/4.
P3: 2/5, 3/4, 5/8, 6/9, 1/1, 4/7.
P4: 1/5, 6/5, 2/5, 3/3, 4/8, 5/9.
P5: 2/9, 1/3, 4/5, 5/4, 6/3, 3/1.
P6: 1/3, 3/3, 5/9, 6/10, 4/4, 2/1.
---------
Read the first line like this: Project P1: the first operation needs resource R2 for 1 minute, the second operation needs resource R6 for 3 minutes, then operation 3 needs resource R1 for 6 minutes, etc. Notice that each project uses each resource but in a different sequence. In the Vladimir problem, all 4 projects have the same sequence of resources (R1, R2, R3).
Mike, can Asta PowerProject find a shorter schedule than Spider Project?
It sounds like the Olympic Games in Project Management software.
Cheers,
George
- 0George Mejtsky ·
Rafael,Wonderful!
Rafael,
Wonderful! Congratulations! It is a very good schedule. It looks like the gold medal will go to the Spider team. If the Asta PowerProject team, or another team, does not find a shorter schedule, gold will go to Rafael for the Spider team.
Rafael, did you produce the great schedule out of the box (without applying user defined priorities)? How long was the calculation time?
Anyway, I must thank you for your time and effort.
Cheers,
George
- 0Rafael Davila ·
George,It takes fractions of
George,
It takes fractions of a second, perhaps faster than the time it takes your sight to follow the cursor. The software is designed to work with thousands of activities per job and a few jobs opened at the same time.
Look at the following video screen capture.
http://www.youtube.com/watch?v=HRTlsExVCGo
It was done selecting the Optimization algorithm, is 100% automatic. The others not necessarily will provide you with a shorter schedule, no matter which prioritization rules you use. The bigger the schedule the more you will notice the difference between Spider and the rest.
At times it is better to use the other methods as to have some control, especially when using "Apply activity prioritieas" and "Apply phase priorities" in addition to other selected on the Priority selection box. Then when in trouble go to full optimization, here the Priority selection box will be dimmed and the software will look for full optimization without regard to a pre-defined priority, perhaps in Optimization modes it searches some prioritization rules under several layers, if this makes sense.
The following screen will show you the resource leveling options screen.
You can download the Spider File for your use with the demo so you can explore it yourself and find out if there is any error.
http://www.mediafire.com/?a1iw802b74gema2
If you do not work multiple jobs linked together or sharing resources, each job thousands of activities Vladimir might help you select the best option for your needs, it is a scalable product.
Best regards,
Rafael
- 0Vladimir Liberzon ·
Rafael,thank you for your
Rafael,
thank you for your help.
George,
usually initial information for such projects is not activity durations, but volumes (quantities) of work to be done on activities and productivities of assigned resources. Activity duration is calculated as the ratio of volume of work and total productivity of all assigned resources.
You can also assign skills necessary for doing the job. If resources that have necessary skill are known Spider will select resources to be assigned basing on default or user defined priorities and resource availabilities. In this case activity durations are not known before scheduling because different resources have different productivities and durations are calculated in the process of project scheduling when assignments are selected.
Best Regards,
Vladimir
- 0George Mejtsky ·
Vladimir,Thanks for your
Vladimir,
Thanks for your information about activity duration in project scheduling. I am still learning and learning. Raf selected Optimization Plus method on the Resource Constrained Scheduling Options form. How does the method optimize the schedule? Raf mentioned that perhaps the method searches some prioritization rules under several layers (iterative heuristics?). By the way, why Spider schedules are much shorter than Preactor schedules?
Rafael,
Can you run my problem (6x6) again and this time with Backward Direction (instead of Forward) set on the Resource Constrained Scheduling Options form? You might find a shorter schedule with 55 minutes total duration, I hope.
It would be very useful if somebody would solve Vladimir and my problems by other project management software, like Mike with Asta. So we could compare them by quality of resource allocating.
Best Regards,
George
- 0Mike Testro ·
Hi George I would love
Hi George
I would love to help but I am heavily involved in an arbitration.
You can download a 30 day trial version of Asta PowerProject v 11.04 at
Best regards
Mike T.
- 0Vladimir Liberzon ·
George,we do not make our
George,
we do not make our optimization algorithms public. It is rather complex iterative heuristics. We did not compare Spider schedules with Preactor's. This information we got from our customers in Brazil.
I tried backward scheduling but the result was not improved. It is possible to try options applying user defined priorities but it is time consuming and hard when the schedules consist of many thousands activities. We tried to make the default schedule as close to optimal as possible with very limited number of iterations. Resource scheduling shall be very fast to provide good schedules at the start of each shift and the schedules where Spider is used are usually large.
Best Regards,
Vladimir
- 0George Mejtsky ·
Vladimir,Thanks for trying
Vladimir,
Thanks for trying backward scheduling. I kind of agree with Rafael that “The bigger the schedule the more you will notice the difference between Spider and the rest.” So here is a bigger production problem with 10 projects and 10 resources to show a bigger difference, I hope.
----------------------
Problem (10 projects, 10 resources):
P1: 10/29, 1/78, 2/9, 3/36, 4/49, 5/11, 6/62, 7/56, 8/44, 9/21.
P2: 10/43, 2/90, 4/75, 9/11, 3/69, 1/28, 6/46, 5/46, 7/72, 8/30.
P3: 1/91, 10/85, 3/39, 2/74, 8/90, 5/10, 7/12, 6/89, 9/45, 4/33.
P4: 1/81, 2/95, 10/71, 4/99, 6/9, 8/52, 7/85, 3/98, 9/22, 5/43.
P5: 2/14, 10/6, 1/22, 5/61, 3/26, 4/69, 8/21, 7/49, 9/72, 6/53.
P6: 2/84, 1/2, 5/52, 3/95, 8/48, 9/72, 10/47, 6/65, 4/6, 7/25.
P7: 1/46, 10/37, 3/61, 2/13, 6/32, 5/21, 9/32, 8/89, 7/30, 4/55.
P8: 2/31, 10/86, 1/46, 5/74, 4/32, 6/88, 8/19, 9/48, 7/36, 3/79.
P9: 10/76, 1/69, 3/76, 5/51, 2/85, 9/11, 6/40, 7/89, 4/26, 8/74.
P10: 1/85, 10/13, 2/61, 6/7, 8/64, 9/76, 5/47, 3/52, 4/90, 7/45.
----------------------
For understanding how to read this notation, see my previous problem.
Best Regards,
George
- 0
- 0George Mejtsky ·
Vladimir,Great! Thank you for
Vladimir,
Great! Thank you for your time and effort. How long was the calculation time? It looks like the second gold medal for Spider. When you have time, can you try to improve this schedule by applying priorities? Can you describe the process of applying priorities? As I understand, you select a priority or set of priorities and calculate the schedule, and then you select a different priority (rule, heuristic) and calculate a new schedule, etc. You repeatedly calculate schedules with different priorities, and then you select the best schedule found. Is this process the same in Spider?
In Spider, do you have some random priority (random heuristic) which would select randomly? I would like to know the length of the random schedule or an average schedule. If we know the average/random schedule then we could compare our best found schedule with the random schedule. We might find that our schedules based on priorities might not be better than the random schedule. I hope it is not the case.
The first production problem (6 projects and 6 resources, 6x6) is the smallest and one of the easiest instances found in the standard job shop scheduling benchmark set. This problem is called FT06 and has optimum makespan 55. Spider found the schedule with makespan 56 which is only 2% longer than the optimal schedule. Frankly, it is not very far from the optimum indeed.
The second production problem (10x10) is probably the most famous job shop scheduling problem, called FT10. FT10 has optimum makespan 930 which is very difficult to find. Spider found the schedule with makespan 1016 (16 x 60 + 56) which is 9% longer than the optimal schedule. So there is enough space for improvement here. How much can you improve it? I think it is a very good schedule for the default "out of the box" solution. Can anybody find a better default "out of the box" schedule with a different software? I doubt.
I hope I made no errors in defining FT06 and FT10. You can find all the benchmarks defined in http://www.eis.uva.es/elena/Elena%20Perez%20Vazquez_archivos/files_optimaJSSP/jobshop1.txt. An additional information about the benchmarks is in http://www.eis.uva.es/elena/JSSP/index.htm.
In real world projects (large and complex), the optimum schedule is not reachable. Therefore, we do not know how far our schedule is from the optimum schedule. However, if we can get a random/average schedule then we can compare our schedule with it to make sure that our schedule is better than the random one, hopefully. That’s why, I propose to include the random priority rule in Spider, if it is missing.
Best Regards,
George
- 0Vladimir Liberzon ·
George,when I wrote about
George,
when I wrote about applying priorities I meant priorities of certain activities or projects. When the scheduler receives automatic scheduling result he/she can try to improve it applying user defined activity/phase priorities (just numbers).
Spider does not have random scheduling and does not apply different priorities selecting the best result. Our algorithms were created for scheduling of very large projects (with hundreds of thousands activities) and shall be very fast to be practical. Both sample schedules that you proposed were calculated in less than one second time.
Applying random heuristics can produce good schedules but is not ptactical in project management. Project life cycle can be measured by years and the schedule is revised at least each week. It is necessary to be able to get the same or similar schedule after minor changes. Random priorities are hard to repeat.
Thank you for the benchmark reference. Comparing Spider schedules with optimal we can find the ways for further improvements.
I am curious about the results produced for the same schedules by production scheduling programs. I know PM software market but did not work with MES systems.
Best Regards,
Vladimir
- 0Rafael Davila ·
George,Sequential application
George,
Sequential application of Optimization Plus and then Advanced using Super Float as Priority will yield better results, and this is without using activity priority. Don't ask me, trial and error, brute force, took me less than 2 minutes though.
http://www.youtube.com/watch?v=KqPzTLX_Gb0
What stands out is that even a schedule known to be difficult to optimize is not that far from optimum with Spider Project Optimization Plus out of the box. I would dare to say on real life jobs Spider will be between 6% and 0% of optimal with an average of 3%, with a distribution close to 3%.
No way you can consistently get there using preferential links as to mimic true resource leveling.
Believe me I have seen software that can go as far as 40% over Spider, say 43% over optimal, and this is unacceptable.
In schedules where partial assignments are allowed Spider stands out as it can even allocate for variable partial assignment. Partial assignments is the order of the day in construction schedules as well as in architectural design schedules where you have some crews or individual resources assigned to work on several long duration activities the same day.
Variable assignment is a refinement over fixed partial assignment that will make a huge difference when allowed.
Spider Demo is limited to 40 activities but if you want to explore the 10x10 schedule maybe using the Free Spider viewer you can explore the files. You can download the file from the following link.
http://www.mediafire.com/?65yqw27jtx48ys4
Regards,
Rafael
PS. The calculation time is always at a blink of the eye, as soon as resource leveling icon is clicked as seen on the video clip.
- 0Rafael Davila ·
Anyone knows what P6 yields
Anyone knows what P6 yields out of the box?
I do not have P6 but exported it into xer file so maybe someone can just load it and run the schedule resource leveling out of the box.
- 0Rafael Davila ·
Vladimir,Lets see if I
Vladimir,
Lets see if I understood:
If Spider is 9% off the best known solution then, Best Known Solution = 1010/1.09 = 926 min
Spider solution out of the box...= 1010/926 =>> 1.09 or 9% off
Rafael trial .........= 16.6167x60 = 997/926 =>> 1.07 or 7% off
Vladimir trial.........= 16.36x60...= 981/926 =>> 1.06 or 6% offP6 out of the box....................= 1427/926 =>> 1.54 or 54% off
p6 best...................................= 1134/926 =>> 1.22 or 22% offI understand you can improve on the 6% as you have not tried individual activity prioritization something I doubt P6 can handle. I also understand you tried all prioritization options that make sense in P6.
Best regards,
RafaelPS 54% off by P6 out of the box is not bad, I had worst expectations.
- 0Vladimir Liberzon ·
Rafael,the best schedule is
Rafael,
the best schedule is 930 minutes (not 926).
Spider best is 16:36=996 minutes, 7% more than the best schedule.
In P6 I tried individual priorities but did not try combinations of priority rules. The number of combinations is too large and potential improvement is small.
- 0George Mejtsky ·
Rafael,What length was your
Rafael,
What length was your schedule of FT10, what makespan? 16:37, (997, +7%)? Can you squeeze out a shorter schedule than Vladimir’s 16:36 (996, +7%) schedule?
I looked at your youtube videos of FT06 and FT10. It is a very fast calculation indeed. I downloaded 101.002.sprj file from MediaFire, but I do not know how to open the file, by which program?
I hope you did not make errors while inputing FT10 definition data. Compare it with the FT10 definition in the jobshop1.txt file (http://www.eis.uva.es/elena/Elena%20Perez%20Vazquez_archivos/files_optimaJSSP/jobshop1.txt)
Regards,
George
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