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Jul

Claim Digger Limitations

Categories: Claim Digger, P6 Calendars, P6 EPPM, P6 Professional, P6 Tricks

Tags: Claim Digger, P6 Calendars, P6 EPPM, P6 Professional, Primavera P6

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by Bill Pepoon

Claim Digger is a convenient tool inside Primavera P6 for comparing schedule files to determine what changes have been made. But there are limitations to what Claim Digger can tell us about a revised file. Experienced Primavera users will recall that Claim Digger used to be a third-party program used to analyze Primavera P3 files. When Claim Digger was incorporated into Primavera P6 several years ago the functionality changed in ways that were both good and bad. Being able to export to HTML format is nice, but having the durations (including float and lags) displayed in hours is inconvenient on schedules with durations that are shown in days.

There are third-party software programs that can do much more than Claim Digger. Still, if you think that Primavera P6 costs as much as having a baby then anything that is “free” will be the most desirable option. So most of us will have to get by with Claim Digger until money starts growing on trees.

Note: in Version 16.1 of Primavera P6 Claim Digger is now called Schedule Comparison and is accessed from the Visualizer program. You will find Scheduler Comparison in the same location (Tools) as Claim Digger but clicking on this button will launch the Visualizer program.

The biggest limitation in Claim Digger has to do with calendars. Here are two scenarios where Claim Diggers will let you down:

Changes made to a calendar, such as revisions to the number of hours per day, days per week, holidays, etc. are not picked up by Claim Digger
Changing the calendar on an activity from Global to Project (or vice versa) is not picked up if both calendars have the same exact name

Indeed, Claim Digger will tell us nothing about calendars other than whether the name of the calendar is different. To demonstrate this for myself I created a Project calendar called “Standard” that is a copy of a Global calendar with the same name. I assigned the Global calendar to all of the activities in a sample project. After creating a baseline (copy) of this project I switched the calendar on the activities in the current project to the Project calendar. Claim Digger did not report any changes to calendars.

I then changed the name of my Project calendar in the current project to “Standard Days” and re-ran Claim Digger. As I expected, Claim Digger reported that I had changed the calendar. Yet other than the name, it was still the same Project calendar. I hadn’t changed anything else. In other words, a false positive.

Owners often run Claim Digger (or ask for the results) so anything that suggests a change when in fact no change was made creates unnecessary confusion. Conversely, a sneaky scheduler could block out additional days in the calendar to coincide with an owner-caused delay in order to exaggerate the impact. An experienced scheduler should be able to figure out if there are any shenanigans going on, but the reality is that P6 is chock-full of hidden traps for the uninitiated.

While we are on the subject, I often refer to myself as a “Primavera P6 Scheduler” because there are in fact specific techniques to scheduling projects with Primavera P6. Case in point: Microsoft Project does not allow two relationships between the same two activities, while in Primavera P6 this is perfectly acceptable. A good scheduler with poor Primavera P6 skills can still make a lot of mistakes because of their unfamiliarity with the program. For the same reason, I tend to be very cautious in Microsoft Project because it is not my bread and butter.

I started using Primavera software in 1987 so in my mind the rules that I observe have almost always been specific to one particular program. Prior to 1987 the software I used was proprietary and followed basic Critical Path Method rules. But CPM does not teach you about Activity Codes, Resource Leveling, and so many other things that are now possible because of software any more than an accountant would automatically know how to create a macro in Microsoft Excel.

“Old-school” schedulers who refuse to stay current on scheduling software get no sympathy from me. I started with proprietary scheduling software, learned Primavera P3, followed by Primavera SureTrak, Primavera Primavera P6, Primavera Contractor, and Primavera P6 EPPM. Not to mention all of the other programs like Microsoft Office that I have had to learn over the years. I had to learn WordPress just to type this silly blog!

Jun

The Schedule That Can Be Beat

Categories: Activity Relationships, logic, Primavera P6

Tags: Activity Relationships, Critical Path, Finish-to-Start, logic, Longest Path, Primavera Contractor, Primavera P6

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by Bill Pepoon

My wife and I recently participated in a group hike to see the new land acquisition by our homeowners association. We own property in a 7,000 acre resort in the Sierras and the new parcel adds several hundred more acres of wilderness that will prevent development near our resort. The problem was, our group leader had told us in no uncertain terms that the last bus back to the resort would be leaving at 5:15 pm. Yet here we were at 4:00 pm still hiking in the wrong direction and realizing we had at least an hour of strenuous hiking uphill to the staging area. So we turned around and headed back. Our group leader was clearly cutting it a little too close.

I feel the same way about scheduling. Yes, there will always be critical activities, but they are of course only critical because other activities are, well, less critical. But if the longest path of activities are themselves quite aggressive then we are only setting ourselves up for failure. So my preference is to have a schedule that can be beat.

I am not talking about sequestering float. You may have heard about strategies to hide float in a schedule. This all started several years ago because nearly all construction contracts in the U.S. state that float belongs to the project and is therefore not for the beneficial use of just one party. The contractor or the owner can use the float, with dibs belonging to whoever grabs it first.

Contractors who felt more entitled to the float began devising ways to hide some of the float by tying activities to unrelated work that starts sooner than the more obvious successors. This removes float from the schedule and makes it more likely that an owner delay to a task will also delay the project. A non-critical activity can quickly become critical because it has very little float. For this reason, the sequestering of float is often prohibited in construction contracts.

In my case, however, I am only trying to avoid being too aggressive with activities that are on the critical path and for this reason I choose the least ambitious type of relationship for the majority of my activities: Finish to Start. My goal is to make roughly 80% of the relationships in my schedule Finish to Start. This percentage can be checked using the DCMA checklist available in P6 Web. DCMA stands for the Defense Contract Management Agency. This checklist – called Check Schedule in P6 Web – can be seen below:

You set up the parameters of the schedule in this menu. Once Check Schedule is run, the results appear in a separate window, seen below:

At a glance I know whether I achieved my goal of making 80% of the activity relationships Finish to Start. Other goals include managing durations and relationship lags. Anything in green is in compliance while red indicates not in compliance with the specified parameters.

My strategy of primarily using Finish-to-Start relationships is a direct result of the early years of CPM scheduling, when Activity-on-Arrow (AOA) was the dominant scheduling technique. In those days, the arrows represented tasks, whereas the nodes (circles in most cases) were the activity identifiers. Because of this technique, each task had two nodes referred to in this order: the I-Node and the J-Node. So you would see something like Activity ID 1000-1005. This technique was also referred to as the Arrow Diagramming Method (ADM).

The Activity-on-Node (AON) method became very popular in the early 1990s and was certainly spurred along by Primavera Systems’ decision to drop Activity-on-Arrow altogether when the first Windows-based version of Primavera Project Planner (P3) was released in 1994. Ignoring this brief history of scheduling software for a moment, consider that if the arrow represented the activity, then all relationships were Finish-to-Start. The J-Node of the predecessor was also the I-Node of the successor. Leads and lags were non-existent. The predecessor(s) always had to be complete before the successor could start. This can be seen in the following Activity-on-Arrow diagram:

We used to split activities into percentages so that, say, the first 25% of drywall hanging could start as soon as 25% of the walls had been framed. This effectively became the lag that we use today with Start-to-Start and Finish-to-Finish relationships. Otherwise, it was fully expected that some work would start out-of-sequence, meaning the successor starts before the predecessor is finished.

By the same token, Finish-to-Start relationships are far more likely to generate out-of-sequence progress in today’s precedence schedules. And my response is “great!” You are beating my schedule! I have set you up for success, not failure. Now, I realize some people are bothered by out-of-sequence progress, but unless there is truly a “bust” in the logic or the result of unexpected delays I see this as a positive sign.

There is another benefit to the Finish-to-Start relationship. It is more likely our resources will not become over-allocated. Older schedulers like myself used logic to limit the number of resources required because the scheduling software was too primitive to do this. We called this type of logic “crew restraints” and I still use this technique today. The resource leveling feature in Primavera P6 is not always the best option for controlling the allocation of resources. And besides, if the schedule is not resource loaded then leveling is not an option.

My attitude often comes down to this: prove to me you can get ahead of my schedule and I will modify the logic accordingly. Until then, my logic assumes a more linear progression of the work and is therefore more forgiving. And everyone will feel better because the project end date does not keep slipping. What could be better than that?

Apr

My Least Favorite Activity Type

Categories: Activity Types, Level of Effort, P6 EPPM, P6 Professional, WBS Summary

Tags: Activity Types, Level of Effort, Primavera P6, WBS Summary

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by Bill Pepoon

While I consider my self pretty adventurous when it comes to Primavera P6, I admittedly have little use for one particular activity type, the WBS Summary. To review, the WBS Summary calculates its Start and Finish date (and therefore, duration) from all other activities that have the same WBS code. On the surface, this seems like a great idea because logic is not required. The WBS Summary is the only activity type in Primavera P6 that works sans logic. And this is what I do not like about it.

I always check the Schedule Log before I publish a schedule. As you should know, the Schedule Log has a topic called “Warnings” that discusses, among other concerns, the number of activities that are missing predecessors or successors. The correct number of “open ends” would of course be two; the first activity will not have a predecessor and the last one will not have a successor. No other answer is acceptable. Owners will also be checking the Schedule Logs during their reviews. Open ends are an easy way to get a schedule rejected.

Because the WBS Summary does not want or need logic, it creates what appears to be a de facto mistake in the schedule. If the person reviewing the schedule figures out that the open ends are due to this particular activity type, then perhaps they would accept the schedule regardless. But it has been my experience that owners do not want to hear any excuses as to why some activities have logic and others do not. Open ends are an unnecessary distraction from other items (sequences, durations, coding, etc.) that need to be checked.

It is possible to add relationships to a WBS Summary to make the open ends disappear, but this basically defeats the purpose of having them in the schedule in the first place. Why not use the Level of Effort instead? The Level of Effort also calculates its dates and duration automatically, but requires logic. Therefore, the Level of Effort does not create any concerns in the Schedule Log. Both of these activity types can also have resources assigned, so nothing is lost by switching to the Level of Effort.

Logic can be added to a WBS Summary without affecting the way it calculates its dates and duration, but again, why not use the Level of Effort instead? While they may seem interchangeable, the Level of Effort demands logic, and therefore forces us to add proper relationships. The WBS Summary is a little too accommodating. I want my activity types to enforce good habits!

Better still, the Level of Effort can transcend more than one WBS code which makes it far more flexible than the WBS summary. If I really need to see the dates and durations for WBS codes I can Group by WBS and choose to Show Group Totals. This saves me the trouble of adding a bunch of WBS Summary activities to my schedule for no other purpose than seeing summary dates and durations.

In the screenshot below, the WBS Summary activity is purple. Yes, this activity tells me the Foundations start on May 17 and finish on June 28, 2016 and have an overall duration of 30 days. Yet the same information appears in the Group Totals:

So there is no additional benefit to adding the WBS Summary activity if the only information being provided are the summary dates and duration.

I know some users are adding WBS Summary activities as a simplified way of cost loading a schedule from the top down. They put all of the costs in the WBS Summary activities rather than the actual work tasks. But Primavera P6 has a tool called Top Down Estimation that is better suited for that purpose. While it is possible to specify a non-linear distribution curve for resources, the reality is that you are still treating every day as having the same value. That is simply unrealistic.

A Primavera P6 compatriot did mention to me a reason why he uses the WBS Summary activity on a temporary basis. When Microsoft Project schedules are imported into Primavera P6, the summary bars are imported as activities. He uses the Microsoft Project summaries as temporary placeholders for checking logic and durations. Similarly, I will use the descriptions of the Microsoft Project summary activities to build my WBS codes before deleting these superfluous tasks,

Feb

3 Strategies for Weather in a Schedule

Categories: P6 EPPM, P6 Professional, P6 Tricks, P6 Web, Primavera P6

Tags: Calendars, Contingencies, Primavera Contractor, Primavera P6, Weather

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by Bill Pepoon

Unless you are working indoors, weather is always a consideration when building a CPM schedule. Somehow, normal weather must be addressed for any work that can be impacted by inclement weather. Our only concern should be normal weather; unusual weather is an excusable delay. This of course raises the issue of how do we determine what exactly is normal weather? Contracts often mention that time extensions will only be granted for abnormal weather without defining normal weather. It is easy to find weather data: in the United States the best source of historical weather conditions would be the National Oceanic and Atmospheric Administration. The NOAA has records for thousands of weather stations around the country that in some cases go back a hundred years or more.

Even so, there is not a single standard for applying NOAA data. Should we take the average for the past four years to determine what is normal? Five years? Six? Federal contracts generally rely upon an average of the last ten years to determine normal weather conditions. (As a personal aside, I have lived in California for 11 years and the weather during the past four years has been radically different than what I first encountered in 2004). Most private construction contracts are unfortunately silent as to what sort of average might be considered reasonable.

The U.S. Army Corps of Engineers is probably the best example of how to specify normal weather. The USACE typically tells contractors how many days of inclement weather to include in the CPM schedule each month. NOAA data would only tell us the average temperature and precipitation, which leaves open to interpretation how a day with, say, 0.1″ of precipitation should be treated. For good or bad, the USACE specifications leave no doubt how many days should be blocked out for weather – not including weekends and holidays. Contractors can not claim they thought it would only rain or snow on weekends!

Some State agencies use a methodology similar to the USACE. Last year I was teaching a highway contractor in Minnesota how to schedule projects using Primavera P6. Someone pulled out the specifications for an upcoming project. Glancing down to the weather provisions, I was not surprised to see that the Minnesota Department of Transportation expected contractors to block out 20 days for inclement weather in January beyond weekends and holidays. In case you are wondering, that wipes out the entire month! I was there in March and it was still below zero degrees in the morning. Winter work is nearly impossible outside unless you are ice fishing.

Sometimes, the contractor does not have to address inclement weather at all. The California Department of Transportation (CalTRANS) specifies contract durations in working days. As the project moves along CalTRANS tallies only the days the contractor is able to works. Bad weather days are not counted. As you might have guessed, this means the project end date shown in the baseline schedule assumes perfect weather and therefore is unlikely to be maintained.

Once we have established some sort of standard for normal weather, we can then move on to a strategy for incorporating this weather into the CPM schedule. Below are the three basic strategies that I use, in my order of preference:

I. Add Normal Weather to the Work Calendar

If the owner has already told me how many days of normal inclement weather to anticipate, it is logical to block out this number of days as if they were holidays. While it is not possible to distinguish a weather day from a holiday in Primavera P6, I try to put my weather days on any Tuesdays, Wednesdays and Thursdays to avoid Monday holidays like Labor Day, Memorial Day and Presidents Day. Obviously Thanksgiving is always on a Thursday but otherwise this works pretty well. NOAA data can even tell us which days of the month typically have the most precipitation if we want to find the best candidates for weather days. I also have a Project Notebook Topic I created in Primavera P6 called “Weather” that I use to list the weather days included in the schedule. This removes any doubt as to why these days were blocked out.

This approach does require two work calendars, however. One work calendar will be for the weather-sensitive work while the other will not include any weather days. After all, shop drawings are not affected by weather and there are usually some field activities that take place indoors. Otherwise the two calendars will probably share the same holidays.

At the end of the month, many schedulers like to replace the planned weather days with the actual weather days. This creates a historical record of when the inclement weather occurred. But actual weather days are presumably being tracked elsewhere so I consider this step to be optional.

II. Create a Contingency Activity for Normal Weather

I started using this strategy in the 1980s as a way to show early completion. The contractor would plan to finish the project early so we needed an activity to bridge the gap between the early completion milestone and the contractual completion milestone. Not all owners would accept the contractor’s right to finish early. In some cases the owner would issue a no-cost change order to modify the contract completion date. Basically, the owner was calling the contractor’s bluff. If the contractor figured he could finish early then why not make that the new contract completion date? Otherwise, the contractor might submit a delay claim based on not being able to finish the project early even though the owner never requested the earlier completion date.

On some projects the bid documents are held in escrow; if a delay claim is submitted the bid documents can be reviewed to see if the contractor based his overhead costs on the shorter project duration. A CPM schedule that shows early completion is often viewed with suspicion unless there is further proof. But in some cases the contract documents specify that early completion is not allowed. The contract effectively becomes a professional services agreement with a fixed time frame.

Normal inclement weather can also be treated as a contingency. The number of expected weather days are added up and inserted into an activity between early completion and contract completion. In this case, however, we are not really expecting to finish early; the contingency will disappear if the total amount of normal inclement weather is realized. During each update we reduce the remaining duration of the contingency activity by the number of actual weather days incurred. In theory, there will be no more weather days once the remaining duration reaches zero days. Otherwise, the contractor is entitled to a time extension.

Both the first and second strategies require an analysis to determine how many weather days are to be expected over the life of the project. Unless the number of weather days are specified in the contract there could be disagreements as to how many days should be included. A smaller number helps the contractor with delay claims while a bigger number protects the owner against the very same claims. Activity durations should be based on perfect weather, as normal weather is accounted for by either the calendar or the contingency.

III. Add Normal Weather to the Activity Durations

This is the oldest strategy and does not require as much effort as the other strategies. The contractor simply adds additional time to the activity durations based on the expected weather. I list this strategy last because it is nearly impossible to verify how much time was added for weather unless the contractor keeps detailed notes (such as using an Activity Notebook Topic in Primavera P6 to explain where the days were added). Moreover, the contractor needs to know what time of year each activity will take place before he can add the right amount of time. For this reason schedule logic is needed first so that the start and finish dates are reasonably accurate. But the reason I list this strategy last is that if an activity is delayed the added time for weather may now be too much or too little. Constant monitoring is required to ensure that activities have not moved into a time frame with different weather conditions.

Update: a member of the Association for the Advancement of Cost Engineering took exception to this third method after my original post was published. He felt this method should never be used and referred to the AACE’s Recommended Practice for addressing weather in a schedule. But he was missing the point. I have used this third method for years without any issues. Keep in mind that if the weather days are shown on the calendar or as a contingency activity the contractor has boxed himself into a corner. He cannot later claim he expected fewer normal weather days.

The contractor may very well want to give himself some “wiggle room” to clarify his understanding of normal weather once a dispute arises. And who can blame him if the owner does not specify the number of weather days either? The owner is legally responsible for any ambiguities in the contract documents. Conversely, if the contractor feels he has been treated fairly by the owner on all other matters, he may be willing to concede a few weather days that he otherwise felt entitled to claim.

Let’s use liquidated damages as an analogy. Liquidated damages clauses have been around for decades. A contractor is put on notice that a specific amount of money will be withheld by the owner for each day he is late. Liquidated damages are an approximation of the financial impact caused by the project being delivered late. As such, liquidated damages cannot (and are not required to) be proven. The contractor may think the liquidated damages are outrageous, but this is not a matter for negotiation.

Yet the same owner has no clue how many days should be included in the schedule for normal inclement weather? There are multiple sources of historical data to help him make this decision. So perhaps the owner wants a little “wiggle room” as well. He has the information necessary to make a decision; he just decided to leave the contract ambiguous. Shame on him.

The bottom line is that most construction contracts do not adequately address the definition of normal weather. AACE’s Recommended Practice is not the solution either since it still leaves this matter open to interpretation.

What is your favorite method of addressing inclement weather? I can be reached here.

Dec

Viewing Data in a Shared Database

Categories: Databases, P6 EPPM, P6 Professional, P6 Web

Tags: Multiple Users, Primavera P6, Shared Database

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by Bill Pepoon

Primavera P6 users who share a database with other users will not see the most current changes being made by the other users right away. The other users must commit their changes, and then the user will be able to refresh his or her screen to see these changes. We will discuss how changes to a project are committed to the database first.

Most users commit their changes to the database without realizing it. For that matter, many users are not even aware of any specific procedures for committing changes. Yet it happens on a pretty regular basis as long as the other users take one of the following actions:

Closing the application
Choose File, Commit Data (F10)
Choose File, Refresh (F5)
Summarize Projects
Apply Actuals
Schedule
Import/Export
Delete a resource
Delete a project
Change a user password
Open a project
Close a project
Save a project baseline
Save a layout in Tracking View
Add a resource and complete the New Resource Wizard
Create a new Report using the Report Wizard
Import or Export a report
Select a baseline project to use and click OK
Edit a calendar from Enterprise, Calendars
Delete a Resource Shift from Enterprise, Resource Shifts
Modify a Resource Shift and click Close
Leveling resources

Whew! And that is not even the complete list! So if the other users are moving around the program quite a lot they will probably commit their changes to the database by “accident”. Which is fine, but if someone is adding a long list of activities and doing nothing else, other users who open the same project will not see these changes. But as seen below, switching from one of these views to another will also commit changes:

Projects View
Reports View
Resources View
Tracking View
WBS View
Work Products and Documents View
Activities View

Once the changes have been committed to the database then other users simply need to refresh this data on their screen. Thankfully, this list is pretty short:

Choose File, Refresh
Save a copy of the current project as the baseline
Choose Tools, Check Project Integrity
Selecting Apply on various windows within P6

The user making changes would not lose them because he or she failed to commit changes for the simple reason that closing Primavera P6 automatically commits changes. For that matter, I have never seen a situation where data was lost even when Primavera P6 crashes. So the only concern is whether other users are seeing the latest revisions.

Jul

Put Your Primavera XER File on a Diet

Categories: Oracle XE Database, P6 Professional, POBS Table, Primavera P6, Primavera XER

Tags: Oracle XE Database, POBS Table, Primavera P6, Primavera XER, XER Size

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by Bill Pepoon

You have probably noticed that after using Primavera P6 for a while your XER files seem to be getting bigger. Actually, a lot bigger. Files that used to be under 1 MB are now more than 10 MB. This slows down the importing of XER files considerably and makes it harder to email files without using a large-file service like Hightail or Dropbox.

According to Oracle, this problem affects Versions 7.0 and later.

The XER file format is the most popular way to exchange project data between databases. As a consultant, I always have to send my files to the client. There is another Primavera format – XML – but these files tend to be rather large compared to Primavera XER. The beauty of the XER format is that it is text-based, which normally results in a very small file.

Nevertheless, XER files have a bad habit of getting rather chubby, if not downright HUGE. This would be understandable if it served some purpose. Unfortunately, the increased size is a complete waste of space. And in some cases it takes so long to import the XER file that P6 effectively locks up. Not good.

Specifically, the problem is the POBS Table. Join the club if you have never heard of this data field. Here is the official explanation from Oracle as to the purpose:

Functions related to table POBS have not been implemented yet so the table has not been put to use. The table may be removed in a future release.

You do have to wonder, if Oracle has not found a purpose for the POBS Table yet, why has its use persisted for so long? This is not the first time a feature showed up without a purpose. For several years Primavera P6 displayed a colored bar next to the Activity Code Values. The default color was blue. Regardless, changing the color did nothing because the feature was intended for Visualizer, which had not been incorporated yet:

Since the POBS Table is not used at all, we might as well delete it. Granted, if your XER files are rather small it is not a necessary step. Until recently all of my XER files were reasonably sized considering the size of the projects. But starting several months ago my XER files started gorging themselves. A POBS Table with a few dozen lines suddenly had thousands of lines. Deleting the POBS Table became a necessity for me.

Assuming you are using an Oracle database it is rather easy to delete the POBS Table in the database so that export files do not include this table by running the following statement inside the database after backing it up:

delete from pobs;
commit;

**UPDATE** Please see my post regarding how to Delete POBS Data in an Oracle XE Database for more detailed instructions on how to execute the above commands.

Files being imported into the database, however, most likely will have the POBS Table. So it may become necessary to modify the XER files prior to importing them. Here are the steps:

Make a copy of the XER file (just in case!)
Open the XER file in a text editor like Notepad
Find (Ctrl+F) the line that starts with %T POBS
Select the following lines that start with:
1. %T POBS
2. %F (including all line content)
3. %R (including all line content)
Stop at the next %T
Delete the above lines
Save the XER file
Import the XER file

Below is a screenshot showing each type of line that must be deleted:

Note that lines that start with %R may number in the hundreds or even thousands. The above image does not reflect the thousands of %R lines that existed in this particular XER file.

The next %T will be very close to the end of the file. The rest of the lines pertain to project data that should not be deleted, which is why we stop at the next %T. The biggest headache is getting all of the %R lines highlighted.

Still, deleting the POBS Table can yield startling results. Starting with a XER file that was 14.4 MB (14,377 KB) in size, I employed the technique described above to delete the POBS Table. The new XER file was just 105 KB (!)

It is always a good idea to make a backup copy of the XER file just in case you delete the wrong lines. But otherwise this is a quick and easy way to drastically reduce the size of XER files.

Update: starting in 2016, Oracle introduced SQLite as the default database for standalone users. This new database does not use the POBS table and therefore the problem I am describing no longer occurs.

Any comments or questions? Please email me.

Jun

Time-saving Tricks in P6 You Must Use

Categories: P6 Professional, P6 Tricks, Primavera P6

Tags: P6 Tricks, Primavera P6, Primavera P6 Tricks, Primavera Tricks

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by Bill Pepoon

Primavera P6 will save you a boat-load of time while building a schedule if you know where to look. And since one of my most recent training clients actually builds commercial fishing boats I suppose the analogy is even more appropriate for them! While there are also several time-saving tricks for updating a schedule, today I am going to focus on the building of a brand new schedule. Here are my top five favorite P6 tricks based on 30 years of experience using Primavera software:

1. Fragnets

If we think of the entire schedule as being a network diagram then a fragnet is a sub-network. A fragnet may be just a few activities, or dozens. Traditionally we develop fragnets for two reasons: (1) to represent additional work that is not part of the original scope, or (2) to represent repetitive work in the original scope. In the baseline schedule the latter example is how we save time.

I have not truly built a baseline schedule from scratch for quite a few years because I am always copying part of the logic. The first floor logic is copied and used as the basis for the second floor. The northbound lanes are copied and used as the basis for the southbound lanes. Besides just copying a bunch of activities, however, we also need to consider how the Activity IDs can save us time.

P6 really wants us to use prefixes in our Activity IDs. In the Project Default settings we cannot leave the prefix for new activities blank, and why would we? Copying activities without the ability to assign new prefixes would frankly not be much fun. Let’s say that Activity ID FLR1_1000 is layout on the first floor of the building. When this activity is copied for the second floor the new prefix (FLR2) tells us the location while the original suffix (1000) indicates the type of work.

Nearly always my prefixes are based on locations. I want the submittals to have the same prefix, the Stage 1 activities to have the same prefix, and so forth. Some schedulers use the prefix to indicate the type of work, but when I am adding relationships I want the activities in the same location to have the same prefix. Most of my activity relationships will be defined by proximity, not the type of work.

As an alternative, we can copy an entire section of the Work Breakdown System and paste it elsewhere. This has the added benefit of creating a new section in the WBS for the new activities while they are being pasted.

Before copying the activities it would behoove us to make sure the durations and logic are complete so that we can also copy this information as well. In most situations I do want to replicate the durations and logic. Any changes will likely be fairly minor.

The first step is to highlight the activities that are being copied and then paste them. I don’t worry too much about where they should be pasted right away. I may need to create a new WBS or Activity Code for the copied activities so that they stay grouped together.

In the screen shots below you can see what activity information I have chosen to copy and the new prefix I have selected for the Activity IDs:

2. Fill Down

There is no way I could live without Fill Down. It is so awesome! When we try to copy a value in P6 (such as a duration or a calendar) the entire row is copied – that is to say, the activity is duplicated. Which is what I just discussed previously. Fill Down, on the other hand, allows us to copy a single value from one activity to another (or several). Here are just a few of the data fields that Fill Down can copy:

Activity Code
Activity Name
Activity Type
Budgeted Units
Budgeted Cost
Calendar
Duration
Percent Complete Type
Primary Resource
WBS Code

The first step is to highlight the data field that should be copied and highlight the cells below using the Shift key on the keyboard. Then right-click and select Fill Down from the menu. (There is also a keyboard shortcut: Ctrl + E).

But what if we are trying to copy a data field to an activity that is above the current one. Guess what? Fill Down can fill up! All we have to do is use the Ctrl key on the keyboard rather than the Shift key. The Ctrl key also allows us to select non-adjacent cells – something that is not possible when using the Shift key.

In the screen shot below I am replacing the 5-Day calendar with the 5 Day with Holidays calendar:

3. Link Activities

Probably 80% or more of my activity relationships will be Finish to Start in a typical baseline schedule. Because of this, it is faster to make everything Finish to Start and then go back and change the ones that should be something else. This is called managing by exception and it is a huge time-saver. The alternative is to work on one relationship at a time and I have better things to do, such as drink wine and eat chocolate.

Like Fill Down, if we highlight the activities with the Shift key, Finish to Start relationships are added starting from the top row and working down. But if we use the Ctrl key to highlight the activities, the order in which we select the activities becomes the sequence. Regardless, the relationships being added are Finish to Start.

A lot of schedulers seem reluctant to use Finish to Start relationships but it is the most conservative way to schedule work. The more we overlap activities the more resources that are required. In theory, we can “beat” a schedule that primarily uses Finish to Start relationships. An overly aggressive baseline schedule built mostly on overlapping relationships has no fat to trim should we find ourselves behind schedule and not have anyone else to blame.

Grouping is very important when linking activities. It is much easier to select multiple activities when they are somewhat close together. This can be accomplished by giving them the same Activity Code, WBS Code or even the same Activity ID prefix. There are many times when I have not yet “coded” my activities but by sorting on the Activity ID column, the related activities align themselves perfectly.

In the screenshot below I have selected a group of activities to be linked. Since I used the Shift key it does not matter if I highlight them from the top-down or the bottom-up. The result is the same – P6 adds Finish to Start relationships starting at the top.

4. Assign the Same Predecessor or Successor to Multiple Activities

There are times when we want to assign the same predecessor or successor to several activities. For example, all submittals can typically start right after the Notice to Proceed so they share the same predecessor. In my larger schedules I often have a hundred or more submittals that need a predecessor. All I have to do is highlight the submittals in the Activity Table and then click on the Assign Predecessor button on the right-side menu (as seen below) and select my Notice to Proceed activity. This predecessor will then be assigned to all of the highlighted activities. Sure, I could link Notice to Proceed to one submittal at a time, but remember what I said about wine and chocolate?

5. Schedule Automatically When A Change Affects Dates

When linking activities it only makes sense to let P6 calculate the activity dates each time we add or modify logic. Even changing the duration of a single activity with no predecessors or successors will trigger the calculation since the Finish date of the modified activity is obviously a different than before. There is no excuse for submitting a schedule that has not been calculated, yet many users forget to do this one last time after making a few last-minute tweaks.

In case you do not know where to find this setting, I have included a screenshot below. Note that the fourth box from the top is now checked:

When updating a schedule, however, I turn off this feature. It gets a little technical as to why I do this, but the simple answer is that P6 may reject actual dates I am trying to input if the program is constantly recalculating dates on the remaining work. So this trick is only appropriate when building the initial schedule.

What are your favorite Primavera P6 tricks? Please email me.

Mar

Auditing Changes to a P6 Schedule

Categories: Audit, P6 Optional Client, P6 Professional, Primavera P6, Primavera Training

Tags: P6 Audit Trail, P6 Professional, Primavera P6, Primavera P6 Training

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by Bill Pepoon

One of the advantages of Primavera P6 and its use of a database structure is the ability for multiple users to share files. This can also be a disadvantage, however. P6 administrators can restrict users in many ways, but once a user to given permission to do something, well, the hope is that he or she does not make a total mess of things. As a professional Primavera P6 trainer it always baffles me that someone might expect to master the art of scheduling without any formal instruction. There are not too many self-taught painters to my knowledge. Carpenters, bricklayers, mechanics, etc. all go through a training or apprenticeship program to learn their skills.

When Malcolm Gladwell described “The 10,000 Hour Rule” in his best-selling novel, Outliers, he could have very well been talking about scheduling. After I had been scheduling projects full-time for about five years – or roughly 10,000 hours – I felt like I had finally mastered the art of scheduling. And keep in mind, I was working on schedules every single working day. Many Primavera users only touch their schedules once a month during the update process. As a consultant, I was working on several projects simultaneously. In a typical month I would create two baseline schedules and update ten or more schedules.

But I digress. Today I want to talk about “Carl” and his dilemma. Carl attended one of my Primavera P6 classes in Oklahoma after pulling a 12-hour shift at a refinery. So you can imagine that by the end of an 8-hour class he was pretty beat. But he stuck around after class to talk about a specific problem he was having. You see, Carl was one of about a dozen schedulers working on the same project. Refinery shutdowns are very difficult to schedule. Durations are measured in minutes, not days. A six-month shutdown might require 25,000 activities to schedule. No single person could possibly handle this workload.

One particular problem that Carl was having is that he would calculate the schedule (i.e. F9) and there would be loops in the logic. And then everyone would yell at him for fouling up the schedule. Except that Carl was pretty sure he was not the culprit. He was simply the person running the schedule at the end of the day after everyone else had been inputting changes. This was your basic “shoot the messenger” situation. Carl was taking all the blame because he did not know how to figure out who was causing the problem.

While there is no perfect solution to Carl’s dilemma I was able to show him the audit columns in Primavera P6. These columns, available in the Activities Window, provide the following information regarding an activity:

Who added the activity (“Added By”)
When the activity was added (“Added Date”)
The last person to make a change (“Last Modified By”)
The date the most recent change was made (“Last Modified Date”)

These columns can be seen in the screenshot below:

Activity ID E2045 was originally added on February 27, 2015 by user “admin” and then modified about a month later, on March 25, 2015. Obviously we do not know the exact nature of the modification, but we now know where to start looking.

Unfortunately, there are some limitations. Changing the relationships between activities is not considered a modification. So Carl would not be able to identify who made the logic changes that resulted in loops. Still, adding new activities is often the source of a loop in a schedule because of the corresponding new relationships.

Changing an activity duration, on the other hand, is considered to be a modification. Other examples of recognized modifications are:

Assigning a new resource
Deleting an existing resource
Changing a resource’s budget
Changing the Activity Name
Assigning a new calendar

Note that if you are displaying time in the date columns (Edit > User Preferences > Dates) then it is possible to track who made the last changes on a given day.

Claim Digger can of course identify changes to relationships, but can not tell you who made the changes. The audit columns are still the best alternative within P6 for identifying the source of changes.

Keep in mind that only the most recent modification date and time is stored in the audit column so there is no way to see whether more than one user has been making changes to the same activity.

Copying a schedule results in the Added Date and Last Modified Date resetting to the day the schedule was copied, so the audit columns are only useful in the original version of the schedule.

Feb

What “Delete This Row” Really Means in a P6 Spreadsheet

Categories: P6 EPPM, P6 Optional Client, P6 Professional, P6 Web, Primavera Training

Tags: P6, P6 Update, Primavera P6, Primavera Templates, Primavera update

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by Bill Pepoon

During a private Primavera P6 training session last week I was showing my client how to import changes into a P6 schedule using a Microsoft Excel spreadsheet. As you probably know, there are basically four steps involved: (1) create a spreadsheet template inside P6, (2) export the spreadsheet, (3) make changes to the spreadsheet, and (4) import the spreadsheet back into P6. There are a few basic rules to follow, such as not changing the order of the columns in the spreadsheet after it has been exported, but otherwise it is an easy way to share Primavera P6 data with individuals who may not have access to (or understand how to use) P6.

As a consultant, I use spreadsheets all the time for schedule updates. I send spreadsheets to my clients and ask them to provide the status of each activity that has been started or completed since the previous update. I rarely have to input this information manually. This process saves a lot of time and I can focus on more important tasks such as checking the critical path, and looking for open ends and out-of-sequence progress.

Anyone who has used a spreadsheet exported from Primavera P6 has probably noticed the mysterious column that P6 adds at the end. This column is not part of the template created in P6 but always appears in the exported file. While both rows 1 and 2 are column headers, it is the second row that most people notice because of its somewhat cryptic message:

“Delete This Row”

My client understood this instruction to mean that the second row should be deleted prior to importing the spreadsheet back into Primavera P6. And where did they get this crazy idea? From the in-house P6 expert. Granted, it does appear that P6 is telling you to delete the second row. And the real meaning of this instruction does involve deleting a row.

Here’s the deal. Deleting rows in the spreadsheet does not delete the activities when the spreadsheet is imported back into Primavera P6. I sometimes forget to use a filter in my spreadsheet template and when I realize there are more activities in the spreadsheet than I intended, it is often faster just to delete the rows rather than re-export the spreadsheet. And for this reason I also warn my clients that deleting a row in the spreadsheet is not the proper way to get rid of activities that are no longer needed.

The purpose of “Delete This Row” is in fact to delete one or more rows. You type “d” in this column next to any activity that should be deleted from the schedule. When the spreadsheet is imported back into Primavera P6 the activities with “d” next to them will be deleted. It is actually a great way for someone to communicate to me that certain activities should be deleted. In the graphic below, Activity ID 21 has been designated for deletion:

Keep in mind, that when activities are deleted there is a chance that it creates open ends in the logic network, so it is very important to check for missing predecessors and/or successors before publishing the schedule. Otherwise, “Delete This Row” is a very convenient way to get rid of unwanted activities.

Dec

What is a “Planned” Date in P6?

Categories: Constraints, P6 EPPM, P6 Professional, Primavera P6, Schedule Options

Tags: Finish, P6, Planned Finish, Planned Start, Primavera P6, Start

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by Bill Pepoon

Primavera P6 has quite a few date fields that are often misunderstood. Perhaps no date field is stranger than the “planned” date. To begin with, there will always be a Planned Start and a Planned Finish date associated with every activity. In a schedule with no progress (or what we would traditionally call the “baseline” if P6 did not use this designation for target schedules) the following is always true:

Planned Start = Start
Planned Finish = Finish

Once progress is recorded, however, all bets are off. The planned dates will not reflect actual dates, for example. Primavera P6 shows actual dates in the Start and Finish columns, making it easy to see which activities have progress (take that, Microsoft Project!) without having to add the Actual Start and Actual Finish columns. Space is always at a premium in a printout so not having to add the actual columns is a nice benefit.

Here is where it gets interesting. Changing the Planned Start or Planned Finish date on an activity with no progress will change the Start and Finish dates and likewise move the bar in the Gantt Chart. The rules are:

Changing the Planned Start changes the Start date, even if the Planned Start is before the original Start date
Changing the Planned Finish moves the Finish date and changes the Original Duration to match
Changing the Planned Start and Planned Finish will move the Start and Finish dates accordingly
No other activities are affected by changes to the Planned dates of an activity

None of this will happen, however, if the “Schedule automatically when a change affects date” scheduling option is selected. This is because scheduling the project wipes out the changes made to the Planned dates. These are not constraints, after all. The logic was never modified. Which may seem like Planned dates are a cruel trick.

Well, we create logic for a reason. Moving bars around is not scheduling. Logic is supposed to drive dates. A few constraints are okay – although some owners are adamant about having none – as long as they do not cause an interruption to the critical path. Postponing the start of a critical activity would obviously make no sense.

Note that if you change the Planned Start or Planned Finish of an activity with progress, nothing happens at all. The Planned dates will not change.

Changing the Planned dates, really, is mostly a bad idea. But let’s say we all agree that some of the dates in a schedule are not right. So we massage the dates using the Planned columns and then create a baseline. Using the baseline as a guide, we then modify the logic and durations to achieve the new dates. Sort of like tracing a drawing with velum paper.

Comments or questions? Please feel free to contact me.