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May

Scheduling as a Profession

Categories: Primavera Training

Tags: Construction Science, CPM Scheduling, PMI, Primavera software

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by Bill Pepoon

Someone asked me recently if getting a job as a scheduler would be difficult without a college degree. That is not an easy question to answer because it really depends on the industry and employer’s preferences. I personally do not think a college degree is mandatory, but certainly those four years in college should count towards experience. College forces you to learn new skills every semester. At the same time, I have met field-tested individuals who, like the tin man, seemingly need a piece of paper to prove their worth. And it is entirely possible that neither the college graduate or the highly experienced individual has been formally trained for scheduling. A little more effort is therefore necessary on both their parts.

The dictionary tells us that a profession is a paid occupation, especially one that requires a formal education and prolonged training. Doctor, lawyer, accountant, and engineer are widely recognized as professions. In many instances a license or certification is also required. There is a sanctioning body, and an individual can lose their privileges for various infractions.

Does that mean that scheduling is not a profession? There is no mechanism to stop individuals from being schedulers unless companies refuse to hire them. Employers effectively decide who is a scheduler. But do these employers understand scheduling well enough to vet potential candidates? Not always. The right degree listed on a resume is certainly helpful, as well as relevant experience. So scheduling is perhaps a quasi profession based on the expectations of the job market.

Before anyone gets too excited, I am not trying to diminish scheduling by calling it a quasi profession. Rather, I am simply acknowledging by my fraternity brother the doctor has to live up to a higher standard than I do. And I think scheduling deserves a little more leeway. Should a scheduler be formally disciplined for using negative lags? Are constraints allowable? It is a slippery slope to let some group arbitrate what constitutes proper scheduling.

I often think of project managers when I think about schedulers. Project management is also a quasi profession. I meet project managers all the time. Their backgrounds vary considerably. In some cases “project manager” seems more like a job title than anything else. A person can get promoted tot. project manager. Not something you would say about the legal profession. “Yes, you have done such a great job as a paralegal that we are promoting you to lawyer!”

The Project Management Institute is (in its own words) “the gold standard of project management certification. PMI is quite adamant that project management is a profession. But for many years PMI has had a curious problem: fewer members than certified Project Management Professionals (PMPs). I noticed this back in the late 1990s, and the rift just keeps getting bigger and bigger. As of 2016 (PMI has not released data for 2017 yet) here are the numbers:

740,000 PMPs
470,000 members

PMI requires continuing education in order to maintain certification. And we can assume that some PMPs have retired or died during the many years that certification has been available, but I doubt that explains the difference. And besides, not all members are PMPs. The reality is that thousands of people are leaving PMI after obtaining their certification. Your boss tells you to get certified. But once you are certified that is probably the end of the discussion.

Moreover, PMI does not make a college education a prerequisite for certification. But similar to my beliefs, PMI treats a university degree towards experience. Someone with a degree needs a minimum of three years of project management experience in order to sit for the exam, while a person with no degree needs five years. A four-year degree counts as two years of project management experience. I think that is fair. Not everything one learns in college is directly related to project management regardless of the major.

Gold standard or not, PMI does not have the ability to restrict who can be a project manager. Once again, it is the employer who decides what constitutes the prerequisites for project management. But project managers have the advantage of many peers. You are not alone in the organization. A large company could have dozens of project managers. Some of them are probably PMPs.

Several years ago, PMI began offering a certification for scheduling: Scheduling Professional (PMI-SP). This certification does not require PMP certification, and the prerequisites for relevant experience are different: 5,000 hours without a 4-year degree and 3,500 hours with a degree. So a university diploma basically counts as slightly less than one year of work experience. But for someone who only schedules projects part-time, it could take well over a a year to obtain the additional 1,500 hours of experience eliminated by a 4-year degree.

At the same time, however, we must recognize that someone cannot become a proficient scheduler without mastering a scheduling software program. It may be the most important criteria. A 4-year degree and lots of field experience are not good enough to get a job as a scheduler. Computer skills are a necessity, and it is certainly true that the scheduling software programs are complex. Learning the software is an essential part of the training required to be a scheduler.

My father was a civil engineer who started his own construction company in the 1950s. He learned nothing about how to be a contractor in college and he frankly never gave it much thought. By happenstance he started working for a small general contractor and then met two gentlemen who believed he could run his own firm. He figured out his own way of estimating projects based on his dissatisfaction with how he had first been taught to estimate.

The irony is that my dad expected me to become a civil engineer when clearly my future lay with running a construction company. My father did work for Black & Veatch for a few years prior to his long career in contracting but I had no illusions about designing anything. I switched my major to Construction Science (yes, that is where my company’s name comes from) after my freshman year on the advice of older fraternity brothers who were in the Construction Science program.

Kudos to the universities that realized years ago they should be teaching students how to run their own construction companies! Construction Science (Construction Management, et al) is a very common major today. But in my day some construction companies were still more fixated on a traditional engineering degree for probably the same reason as my dad: tradition.

So unlike my father, I learned estimating in college. Not to his standards, of course!

Keep in mind, when my dad started his construction company a license was not required in many states. Any guy or gal with a pickup truck and some tools could call themselves a contractor. The customer decided who was qualified. And on public works in particular the ability to get bonded was a considerable hurdle. An insurance agent could decide if you were indeed worthy based on your assets. Every financial decision my father made was in consideration of how it might affect his bonding capacity.

Getting back to scheduling, I spent perhaps six weeks during my last semester in college learning about CPM scheduling and building my own schedule. That experience alone obviously did not give me a huge advantage over my coworkers at my first consulting gig who never studied scheduling at all. But it helped me to get up to speed a lot faster. My boss also liked the fact that I was losing my hair. He thought that looking older than my years would command more respect from clients. Thanks, I guess.

I studied Critical Path Method scheduling in college – not a typical subject in the 1970s. The personal computer was just being introduced and no software existed that could calculate a CPM schedule on such a device. Primavera Systems did not release its flagship program, Primavera Project Planner or “P3”, until 1983. How would someone even practice CPM scheduling without a computer? My college professor had such a program that he ran on the university mainframe.

Looking back, I realize why CPM scheduling was a senior level class in college. Our professors wanted us to first study not just estimating but also surveying, concrete and masonry design, steel design, drafting, soils analysis – the entire scope of a project. You cannot build a proper schedule without understanding the project scope. It all ties together.

After college, I latched on with a consulting firm that owned its own scheduling software, which they ran on a “mini-frame” computer. Think of something the size of a soda vending machine and you have the right mental picture. But it was not exactly user-friendly: input was via a keyboard with no monitor. Make a mistake and the duration of a task might contain part of the activity description. A duration of “s” was certainly possible. I had to check each line in the computer printout very carefully.

The consulting firm that hired me in 1983 had already been scheduling projects since the 1960s, and two of the original partners were still involved in the day-to-day operations of the firm. I was in fact surrounded by schedulers. I accompanied my boss to jobsite visits to learn the proper procedures for updating a CPM schedule. I never touched any software for my first four years – for the simple reason that data entry was cumbersome. My hourly rate made me too valuable.

Nevertheless, I certainly understood what this proprietary software required from me. Most importantly, I fully understood how the forward and backward passes work based on my studies in college. All scheduling software programs use these algorithms to calculate the longest path of activities and the float values. When the firm purchased Primavera Project Planner in 1987 I quickly learned the features of that program – a much easier task after four years of practice with a simpler program.

Scheduling has always been a profession for me but clearly I had advantages. I studied CPM scheduling in college (formal education) and improved my skills at work (training) as a full-time scheduler surrounded by schedulers. In addition, I had access to several scheduling software programs which allowed me to practice CPM scheduling. For me, scheduling is a profession because I made it a profession.

I meet too many “schedulers” today that are being rushed by their employers to possess knowledge and skills that are simply not there yet. If you skip the formal education then more training and experience will be required. PMI gets it, and so do I. When I started my own consulting firm in 2010 I decided that training would be a major focus. And later this year I will be taking this a step further. Stay tuned!

Feb

Who Owns the Float?

Categories: Total Float

Tags: float, Lag, Project Schedule, Relationships

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by Bill Pepoon

Arguments over who owns the float in the project schedule are common. But unless the contract documents state otherwise, float belongs to whichever party that uses it first. This fact makes no one in particular happy, but a very smart lawyer once told me that the perfect settlement is the one that both parties regret the next day.

Sharing the float is a fair solution, although there will always be times when it seems rather inequitable. The contractor waits until the last possible moment to submit a shop drawing; now the architect is under pressure to return the shop drawing in a timely fashion. The contractor ate the float, making the review critical. But at one time this path had plenty of float. The architect is not happy being put on the spot.

Conversely, the contractor submits the shop drawing very early, but the architect sits on the shop drawing for such a long time that all the float is gone. Now the contractor has no leeway in terms of procuring the materials. Any hiccups during fabrication and delivery will mean the contractor is blamed for the delay, yet he tried so hard to stay ahead of schedule.

As a construction consultant I am caught in the middle. My contractor clients want to own the float, and so do my owner clients. Making people unhappy seems to be part of my job. Nevertheless, it is universally recognized that float belongs to the project. Either party can utilize the float while it is still up for grabs.

There is one brief period of time, however, when only the contractor owns the float. He alone decides how much float each and every activity has in the project schedule. So when is this magic moment? It is quite simple: until the original plan is published the contractor has complete control over the float. Pity then that so many contractors squander the opportunity.

The contract documents clearly give the contractor ownership of means and methods. Certainly there may be some specified sequences in the contract documents (such as for project closeout) but otherwise the contractor decides how to build the project. And this means the contractor controls the float in the original plan. He overlaps work that he feels like overlapping, or makes the work more linear because he wants to conserve resources.

In my experience roughly one-half of all activity relationships in a project schedule are discretionary. We sometimes call these “soft” relationships because the work could be sequenced more than one way. Mandatory (or “hard”) relationships, on the other hand, cannot be violated. The wall has to be built before it can be painted, for example.

When the owner reviews a project schedule only the mandatory relationships can be verified easily. The other half of all the relationships are harder to discern. Why is the contractor starting brick work on the east elevation? Does feeder conduit have to start before branch conduit? But as long as the sequence represents what the contractor intends to follow, the owner has no valid objection. It is what it is.

As with any subject there are a few caveats. I have seen some pretty strange restrictions in contract documents that do affect how logic – and therefore float – can be applied. On one of my projects there was a restriction on what percentage of activity relationships could be Finish-to-Start. Yet on another project I was instructed to use only Finish-to-Start relationships. As a master scheduler I rather resent anyone telling me how to use my tools.

Otherwise, the contractor has so many opportunities to reduce the float in the schedule. Nothing can be considered unreasonable unless it is completely unrealistic. Pour the sidewalks next to the building before starting light poles in the parking lot? Why not? Whether the same trade is involved is immaterial. It is all about hitting dates that make the contractor happy. Besides which, owners often question why activities do not start on their early start dates regardless of the available float.

There is one loophole to consider. The owner and the contractor agree to share the float, per the contract documents. This does not preclude the contractor from crafting language in his agreements with subcontractors to restrict the use of float. In other words, the contractor only has to share the float with the owner. He is not obligated to share float with subcontractors.

Starting with my first scheduling position in 1983 I was told to monitor excessive float. In some cases it is a sign of bad logic. I either had the wrong predecessor (thereby starting too early) or the wrong successor, which allowed the activity to finish late in the project. If I thought the start date was too early I would go shopping for another predecessor that was finishing later than the current predecessor. Similarly, I might look for another successor that starts earlier than the current successor.

Some of you might think this is dishonest, that I am hiding float that otherwise should be there. No, quite the opposite. I am concerned that the float is unrealistic. Who in their right mind would say to a subcontractor, “you can show up as early as March 2nd or as late as September 15th”? Such a range of dates implies uncertainty. I suspect that Primavera P6 introduced two new date columns – Start and Finish – to avoid the confusion of early versus late. Hardly anyone other than experienced schedulers truly understands the concept of float. Trust me.

So we are not “sequestering” float, which is perhaps a nicer term for hiding it. Moreover, I am not a fan of using activity constraints to reduce the float on an activity. Excessive constraints are the bane of my existence. I once spent an afternoon with a client explaining why he needed to get rid of all 150 constraints in his 175-activity schedule. He had originally contacted me because he could not find the critical path. Duh!

When I conduct my final review of the project schedule I consider whether the activities on the critical path make sense. Contract documents sometimes restrict the percentage of activities that can be on the critical path (hint: add more non-critical activities such as submittals if you have too many critical activities). But I must also consider whether activities on secondary paths have too much float. Yin Yang.

There is certainly no worse feeling than a project schedule that seems to suck up all delays due to excessive float. We should not be sharing float that does not really exist. Once the schedule is published it is simply too late to rectify this problem. The float now belongs to the project.

Jan

The P6 Omnibus File

Categories: Baselines, P6 EPPM, P6 Optional Client, P6 Professional, P6 Tricks, P6 Web, Primavera layouts

Tags: Baselines, Layouts, P6 Optional Client, P6 Web, Primavera P6, XML

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by Bill Pepoon

Omnibus (adjective)

Comprising several items.

The most common Primavera export file is “XER” which harks back to the company that developed this enterprise scheduling software in the first place: Eagle Ray. Primavera Systems bought Eagle Ray, and then Oracle bought Primavera Systems. The very familiar “XER” file format in fact stands for “eXport Eagle Ray”.

XER files can only export project data associated with the current project, or all resources or all roles. For someone who needs to transfer all resources or roles from one database to another the XER file can be very useful, but I find this to be a rather esoteric function for the vast majority of users.

But there is another Primavera export file (XML) that can do so much more:

Export all project layouts associated with the current project
Export all (or some) baselines associated with the current project
Import into any other version of Primavera P6

This might also encourage you to create project layouts. By default, new layouts are user-specific and can therefore be applied to any schedule to which the user has access. Project layouts are only available to the associated project (or a copy of that project) which is desirable when the layout has specific features (such as a grouping or filter) that would not be applicable to other projects. The header or footer might likewise contain wording that is specific to one project.

Primavera P6 EPPM users are more accustomed to this method of importing files because the P6 Web interface only supports XML file imports and exports. However, P6 Professional Client (sometimes referred to as P6 Optional Client) can be used to import XER files into a P6 EPPM database. Confusing, yes, but P6 EPPM databases can be accessed via a Web or desktop interface.

The following screenshots show the process for exporting P6 XML files. Keep in mind, you are not required to export any baselines and can also choose which ones to export. Likewise, you do not have to export project layouts:

Here is the sequence for importing P6 files. Notice that we can choose which baselines should be imported:

Pretty simple!

Hopefully you will not think of me as a hypocrite if I admit to sending XER files on a regular basis. But as a consultant I do not need to keep sending baselines to clients if they have already received those files previously. For example, if I sent my client the third update last month it is somewhat redundant to send them the fourth update this month with the third update as a baseline. I also do not need to keep sending project layouts unless I have recently created new ones.

Nevertheless, for the recipient, the XML file has everything needed to view the current schedule and make comparisons to previous versions of the schedule. I find that for my construction claims work it is a great way to transmit my entire analysis of a delay to the client. The only downside might be that XML files are not nearly as compact as the text-based XER files. Roughly speaking, XML files tend to be about ten times larger, which in some cases might exceed the maximum file size for email attachments. Not surprisingly, it also takes longer to export and import XML files.

Dec

My First Herman Miller Chair

Categories: Uncategorized

Tags: Ergonomics, Herman Miller

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by Bill Pepoon

Closing out 2017 I thought I would change gears and talk about something near and dear to me; my posterior. As a professional trainer I am required to spend a fair amount of time sitting down. Now, that might seem easy, but I have learned over the years that my students simply do not have my stamina when it comes to being stationary. They shift side to side, arch their backs, lean forward – anything that reliefs the pressure of just sitting there. My favorite is when someone’s leg makes sudden contact with the metal privacy panel on our training desks with a loud CLANG. That tends to get everyone’s attention.

Our training chairs, however, are not to blame. Given my vast experience with sitting down I know a good chair when I see one. I sit in the same type of chair as my students and they are really quite comfortable. However, I do have an alternative chair in our training center that is rather unusual. It is barrel-shaped with a convex bottom. The concept is similar to those inflatable balls that some people sit on, but that seems a little too Romper Room for my taste. Here is what my alternative chair looks like:

This is the Turnstone Buoy by Steelcase. It is height-adjustable, which is a vast improvement over an inflatable ball. I also do not need to worry about my chair wandering off when I stand up.

A “wobbly” chair like the Steelcase Buoy encourages movement, circulation and strengthens core muscles. The only disadvantage for me is that the padding on top is not particularly thick, so after a few hours I have to switch to a more traditional chair. My natural padding is simply not adequate, which I suppose could be a plus.

But what I really want to talk about today is my first Herman Miller chair. I started thinking about this subject when I read an article that was originally published in Vanity Fair back in 1998, “My First Gulfstream”. The article was written anonymously but the author (a Microsoft executive at the time) has since revealed himself. He was a little embarrassed to be buying a jet when even his own boss (some guy named Bill Gates) did not own one.

Only the top 1% of earners can relate to the trials and tribulations of dropping $10 Million on a used jet and another $2 Million in renovations ($100,000 for a digital phone makes me almost appreciate my Verizon cell phone plan – almost) but his search for the perfect office chair seemed rather pragmatic to me:

“In an unusually reflective moment, I sat down one day and made a list of everything in my life that could be improved. The top of the list was easy enough: my office chair. I realized that I spent more hours sitting in that chair than in nearly anything else I owned. On that basis, I should be willing to spend a huge portion of my income on that chair. As it turns out, that isn’t really possible. Antiques and art pieces can be pricey, but if you’re buying a chair for your behind rather than for status you can get a Herman Miller Aeron for about $1,150.”

Yes, the Herman Miller Aeron chair. I did not read the Gulfstream article until recently (it is available online) but I was in fact dreaming about the Aeron chair back in 1998. Released just a few years earlier, it was/is the perfect office chair. Often imitated, but there is no other office chair that can make work more pleasurable. Here is what Herman Miller’s website says about the Aeron:

“Aeron’s PostureFit SL technology affords the ideal sit — chest open, shoulders back, pelvis tilted slightly forward. Adjustable pads provide lumbar support and stabilize the base of the spine for the perfect balance of ergonomics and comfort. Our breathable 8Z Pellicle suspension seat and back create eight zones of varying tension for optimal support.”

That said, many of us would have to think pretty hard (and get permission from our spouses) before spending $1,150 on an office chair. Heck, back in 1998 the consulting firm I worked for had one email address for the entire company. Anyone trying to reach me via this newfangled technology would have to put my name in the header. I would then wait for a secretary to print out the email for me. When traveling on business my employer would rent a laptop for me because we did not own any such machines.

I left that company in 1999 and moved to Kansas City. My wife had received a promotion at General Electric and I knew someone who owned a small consulting firm there. So it was a pretty easy decision. And when GE offers to move you, things happen fast. On the day that my wife accepted the promotion a Realtor (paid by GE) showed up at our condominium to get the listing started. Within two weeks all of our stuff had been transported from New Jersey to Kansas City.

Meanwhile, I had not stopped thinking about the Aeron. So imagine my surprise in 2001 when I walked into the conference room and saw IT in the corner of the room. Hello beautiful. The meeting starts, with no explanation right away. Finally, the president of the company explains that a friend of his who owns an office supply company was trying to convince him to upgrade to Herman Miller chairs. So we would take turns trying out the Aeron for a week.

Needless to say, nearly every one of us loved the Aeron. But still, I kept thinking that the president would change his mind when he realized how many employees wanted the Aeron. Perhaps it would come down to seniority? A coin-flip?

In the end, everyone who wanted the Aeron got one. I enjoyed every minute I spent in that chair. When I was being recruited by another consulting firm to move to California I regretted leaving behind the Aeron. But I did pick up a gently used Herman Miller chair while in Kansas City. It is not the Aeron but it is such a well-crafted chair that I still use it today in my home office – more than 15 years after I bought it.

When I started my career in 1982 hardly anyone paid attention to ergonomics. But in the 1990s I developed pain in both wrists after several years of trying to use a keyboard on a desk not intended for computer use. That was a wake-up call for me. The thought of being debilitated by pain at the age of 35 was scary. With a more appropriate desk and chair I have not experienced any such pain since then even though I use a computer much more often today.

Being comfortable is no laughing matter. According to the U.S. Department of Labor, musculoskeletal disorders (MSDs) account for one-third of all workplace injuries and illnesses. You may not wear a hardhat or steel-toe boots at work but that does not mean there are no risks. We joke about paper cuts and stapler incidents but the reality is that poor ergonomics cost companies millions of dollars every year in workers’ compensation claims.

With that in mind, I wish you a happy, prosperous and safe 2018!

Dec

What Dollar General Tells Us About Planning

Categories: Critical Path, Planning, Total Float

Tags: CPM schedule, Critical Path, float, Planning, Resources

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by Bill Pepoon

Those of you living in the United States are probably familiar with Dollar General stores. Mostly found in small towns, Dollar General stores sell a wide-variety of lower-priced items. But there is big money in this market. Dollar General currently has 14,000 stores pulling in $22 Billion a year. The CEO of Dollar General, John Vasos, received a lot of press recently on comments he made to the Wall Street Journal that caught my attention as well.

Most commentators seized upon Mr. Vasos’ comments that the U.S. economy was creating more of what they consider to be their core customer – someone making less than $40,000 a year. Dollar General is planning to build thousands of new stores and is moving into metropolitan areas that were not previously identified as their demographic (i.e. the arrive of a Dollar General store in some communities could be considered a backhanded compliment.)

There has certainly been a lot of debate in this country about the percentage of Americans who are unemployed or underemployed (working fewer hours than desired) and how to solve this problem. The disappearance of good paying manufacturing jobs has resulted in many individuals working somewhere else, but for a lot less money. The new job is also far less likely to offer a pension.

Dollar General and other similar “dollar” stores thrive by selling small quantities of items to lower-income households at prices they can afford. These households do not buy in bulk even though it would result in savings. Hence, they are more likely to run out of something and need a replacement quickly. I can buy a 32-pack of bottled water for about the price of three individual bottles at my favorite store so clearly buying in bulk makes a big difference.

But here is the quote by Mr. Vasos that really caught my attention. He was describing Dollar General’s typical customer:

“Doesn’t look at her pantry or her refrigerator and say, ‘You know, I’m going to be out of ketchup in the next few days. I’m going to order a few bottles.’ The core customer uses the last bit of ketchup at the table the night prior, and either on her way to work or on her way home picks up one bottle.”

In other words, the typical Dollar General customer is not a planner. They wait until they are out of something before they buy more. They overpay without thinking. This is not how we manage projects. We do not (CAN NOT) let ourselves run out of resources needed to complete a project. That would be an inexcusable delay. We figure out what we need and make sure sufficient quantities are on hand when it is needed.

The critical path of the project in particular is a difficult taskmaster. We must complete the amount of work we planned each and every work day. It is not good enough to complete tasks totaling 19 days during a 20-day work period. That puts us one day behind schedule. The critical path keeps us honest. I see a lot of arguments at the end of the month when the final tally is taken. “But we did so much work this month”, they will invariably say. “Not enough”, I will reply.

It takes a different mentality to be a planner. We have deadlines based on expectations of quality and scope of work. A bad plan leaves us uncertain as to where we should be at any given time. Every day is a deadline of sorts, because what we did not finish today becomes something else that must happen tomorrow. Granted, we have some leeway with non-critical activities but a recurring problem that I see on many projects is that the amount of float on a secondary task is exaggerated, thereby diminishing its importance. We reap what we schedule.

Planning is all about opportunity. We have many options during the planning stage. Some options are more attractive or feasible, and hopefully the least-expensive option generates the best result. But it can certainly be more complicated than that. The California Department of Transportation (Caltrans) utilizes an “A + B” approach on larger projects: each bidder must specify a contract duration and a price. Both numbers are considered when awarding projects. Caltrans’ experience is that A + B bids result in lower prices and fewer road usage delays.

The longer we wait to make decisions the fewer options that remain. Projects finish on time because we monitor our progress on a regular basis and implement mitigation strategies whenever slippage does occur. We do not use up float for bad reasons but rather to give ourselves flexibility. We do not allow ourselves to run out of ketchup.

Dec

Why Make Open-Ended Activities Critical?

Categories: Constraints, Critical Path, P6 EPPM, P6 Professional, P6 Tricks, Schedule Options

Tags: Constraints, Longest Path, open ends, Primavera P6, schedule options

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by Bill Pepoon

Primavera P6 Professional is obviously a very powerful scheduling program so naturally some of its features exceed the needs of the typical project. I have consulted on projects that span as little as 35 hours to as many as 50 years. Different industries have unique requirements for their schedules as well. Primavera P6 is designed to handle a wide variety of projects. Today I would like to address my reasons for using a feature in Primavera P6 that is rarely used by the typical scheduler: Make Open-Ended Activities Critical. You will find this feature under Schedule Options (Tools > Schedule > Options).

The concept of making open-ended activities critical was introduced many years ago in Primavera P3. And for the longest time I dismissed it as a quirky feature surely not applicable to me. After all, why would I promote an activity to critical status solely because it is missing a successor? That seems akin to me declaring myself the winner of a contest that no one else entered.

Some of my colleagues back in the 1980s figured it was an en easy way to identify activities that should not be critical. Okay, that seems backwards, but the idea was that if some task showed up as critical that did not seem “right” the scheduler would investigate further. But Primavera P3 had a report similar to what we call the Schedule Log in Primavera P6 that was a more definitive (and easier) way of identifying open ends in the schedule. With this in mind, making activities that are missing a successor critical did not seem like the best approach to finding open ends.

I started my scheduling career working solely on construction projects so my viewpoints towards Primavera P3 were based on a single industry. Years later, when I began consulting on a wide-variety of projects I realized another purpose for Make Open-Ended Activities Critical. For example, let’s say I am a manufacturer trying to track progress on several production lines. I would like each production line to have its own critical path, or what Primavera P6 refers to as Longest Path. But this would entail making each production line a separate schedule.

It would be a lot easier to track progress, however, if I incorporated all of the production lines into one schedule. That way I would not have to keep opening up another schedule to track progress. And P3 only allowed four schedules to be opened simultaneously. (Some of you P3 users undoubtedly remember the master and sub-project concept from P3 which was another alternative to what I am describing). But how could each production line have its own critical path without creating separate projects?

Yep. Make Open-Ended Activities Critical. See, by not linking the production lines to each other they would all have an open end at the end of their sequence. So every production line now has critical activities. The float values are not based on the longest of all the production lines. Each production line has activities with zero Total Float. Problem solved!

The concept I just described works the same in Primavera P6 as in Primavera P3. You might be thinking that each production line could have a constraint on the final activity to create zero Total Float and then link the final activity in each production line to some final milestone. Yes, that will work too, smarty pants! It also means that additional open ends do not need to be introduced into the schedule.

Another reason for Make Open-Ended Activities Critical is relevant to projects in any industry. One of my clients currently expects his project to finish early. Owners often don’t allow the original plan to show an early completion date because it might become the basis of a claim (“I planned to finish early and you stopped me”). In this situation the owner allowed early completion. So my client inserted two finish milestones in his schedule: “Projected Finish” and “Final Completion”. The latter milestone matched the contractual finish date.

The “Projected Finish” milestone had no constraint since the date could obviously slip without any ramifications. The “Final Completion” milestone had a Finish On constraint (Mandatory Finish also works) so the date could not move at all. But as you might have guessed, this meant that only the “Final Completion” activity appeared as critical in the schedule. The earlier milestone and all of the activities linked to it (directly or indirectly) carried Total Float values based on the later milestone.

A critical path consisting of just one (the last) activity) would obviously be acceptable to no one. But the solution was quite clear to me. While my client had linked the “Projected Finish” milestone to the “Final Completion” milestone (to avoid unnecessary open ends) we need the “Projected Finish” milestone to have no successor. Then, by choosing Make Open-Ended Activities Critical in the Schedule Options the Longest Path of activities leading up to “Final Completion” all had zero Total Float. Bingo.

Below is how the schedule looked with “Projected Finish” linked to “Contractual Finish”. Not having open ends means there is no logical critical path. Also, the “Projected Finish” milestone is a non-driving predecessor to the “Contractual Finish” milestone, as evidenced by the dotted relationship line:

By deleting the relationship between “Projected Completion” and “Final Completion” and choosing to Make Open-Ended Activities Critical under Schedule Options, the activities leading up to “Projected Completion” are now critical:

Make Open-Ended Activities Critical is not always a necessary feature, but as you can see, it certainly does have a purpose.