March 2017 – TomsBlog

AACE International Annual Meeting 2017

June of 2017 marked my first attendance at the Annual Meeting of AACE International (formerly Association for the Advancement of Cost Engineering). It was in Orlando – kind of a bummer since I had just attended the Construction CPM Conference in Orlando back in January.

Attendees were treated to two excellent keynote addresses: On Monday, Frank Abagnale gave lessons learned from his early life as a globe-trotting teen criminal followed by 42 years in the FBI. (Leonardo DiCaprio played Abagnale in Catch Me if You Can .) On Tuesday, Justin Newton of Walt Disney Imagineering gave an excellent presentation on the use of Cost and Schedule controls in constructing Disney’s latest attractions.

The technical sessions were first-rate, and I was continually facing the need to decide between multiple sessions of major interest that were taking place at the same time. In sum, I wound up participating in four sessions on project risk analysis, two sessions on advanced forensic schedule analysis, and three sessions on advanced planning and scheduling topics. I also sat in on Dr. Dan Patterson’s showcase of his latest AI-assisted, “knowledge-driven planning” effort, called Basis. Judging from Dan’s previous successes with Pertmaster and Acumen Fuse/360/Risk, Basis is going to take project management to a whole new level. Finally, I participated in a very robust business meeting of AACE’s Planning and Scheduling Subcommittee.

Besides participating as a regular member of the association, I presented two papers in the Planning and Scheduling Technical Program. The first is a paper I wrote to address the deduction of resource-driving links in BPC Logic Filter: (PS-2413) Extracting the Resource-Constrained Critical/Longest Path from a Leveled Schedule.

The second is one where I made only a modest contribution in review but agreed to present the paper on behalf of the primary authors who were unable to attend the meeting: (PS-2670) Draft Recommended Practice No. 92R-17 – Analyzing Near-Critical Paths.

The resulting discussions were stimulating, but judging from the quantitative scoring (based on the speaker evaluation cards), there’s some room for improvement in communicating with this audience. Lessons learned: 1) Despite the refereed papers, this is not an academic meeting. Most attendees are seeking professional development (i.e. training) hours on familiar subjects. Presenting on an esoteric subject like the first paper – especially one without means of direct application in the prevailing software – is guaranteed to disappoint some; 2) When someone asks you to present their word-choked slide deck on a subject that you don’t completely own – especially a prescriptive procedure like the draft RP – don’t do it. Nobody will be happy with the result.

I look forward to returning to the annual meeting in 2019.

Microsoft Project Schedule Health Checking and Fixing using BPC Logic Filter

Regular users of BPC Logic Filter will have noticed some modest changes with the recent release of version 1.2. The ribbon has been slightly revised, and two new buttons have been added: “Project Logic Checker” and “Logic Quick Check”. The second is essentially an abbreviated version of the first.

The Project Logic Checker examines every task in the project and flags the following logic issues for closer review or action:

Task Definition Issues

Manually-scheduled tasks (By definition, these are incompatible with logic-driven scheduling.)
Inactive tasks (In MSP 2010, these are essentially ignored. In MSP 2013+ they are essentially included in the schedule calculations as zero-duration tasks.)
External tasks and external links (Scheduling of tasks with external links can change depending on whether the source schedules of the external tasks are available and open.)
(Hammock) tasks made with OLE links (OLE links typically impose persistent logic constraints.)
Summary tasks with Logic (Hierarchical logic can override precedence logic in the schedule calculations and cause confusion.)
Tasks with Logic on Parent Summaries (These tasks may be controlled by non-precedence logic.)
Constraints and Deadlines (“Must Start/Finish On” constraints are “Hard” constraints since they can override logic. In addition, “Start/Finish No Later Than” constraints are included as “Hard” constraints ONLY when “Tasks will always honor their constraint dates” is checked (i.e. the default value). These are always “Hard” constraints according to 2009 DCMA 14-Point Assessment guidance.)
Duplicate Task Names (Duplicate task names force reliance on a task’s outline hierarchy for recognition of task scope. Development and analysis of the project logic then becomes inefficient or impossible.)

TASK Relationship ISSUES

Missing logic; that is “Open Ends,” including Dangling Starts and Finishes. (Schedules with these conditions are unreliable.)
Relationship Lags and Leads (i.e. negative lags) that that are excessive with respect to the associated task durations (Ideally, logic driven schedules use explicit tasks for all time-consuming activities. Substantial leads and lags are incompatible with schedule risk assessment and are generally considered poor practice.)
Relationships that are not Finish-to-Start (Some scheduling philosophies mandate only Finish-to-Start relationships.)
Relationships that are Start-to-Finish (These relationships are extremely rare in actual project schedules, but they are often used incorrectly.)
Merge Points in the schedule (i.e. tasks with a high number of immediate predecessors)
Reverse Logic Flow through the task’s duration; i.e. shortening the task delays the successor, and lengthening the task may accelerate the successor. (See this entry).
Neutral Logic Flow through the task’s duration; i.e. shortening or lengthening the task has no impact on the successor.
Links to inactive tasks (Depending on the MSP version being used, such links can alter the schedule unexpectedly.)

Task Update ISSUES

Invalid Dates, including incomplete work in the past and completed work in the future (with respect to the Status Date)
Splits
Out-of-sequence progress
Tasks that have missed their target/baseline finish date (as of the status date.)

Other TASK ISSUES

Overlong task durations
False Milestones (i.e. “Milestones” with non-zero durations)
Excessive or negative values for Total Slack

Users can include or exclude any desired checks from the analysis – or adjust associated thresholds – using the Checker Preferences.

The tool automatically restricts the view to show only tasks with logic issues, then it presents an output form that a) summarizes the analysis, and b) allows the user to dynamically modify the filter for pinpoint focus.

For example, here is a highly summarized, ~3300-task, proposed recovery schedule for a troubled international construction project. The Settings window confirms that the logic checker will examine most non-resource-related issues but will ignore the long-duration and high-slack checks for now.

Running the Project Logic Checker identifies and presents over 1500 tasks with logic issues (perhaps a hint to the source of the project’s “troubles.”) The user can then use the output form to reduce or expand the view.

Here’s a close-up of the output/filter form, slightly improved from the one shown in the other figures:

For example, by un-checking all but the Dangling Start box and then clicking filter, I can choose to see only the tasks with Dangling Starts, i.e. tasks with predecessors but without start-predecessors.

Then, I can check only the False Milestones box to see – and correct – the 17 tasks that are coded as milestones but possess a non-zero duration.

Of course, if I’m only interested in one issue – Logic on Summary Tasks for example, than I can begin by excluding all the other issues from the analysis. The result is a (slightly) less cluttered picture. This one highlights the four summary tasks with logic and the forty-four subtasks that are (or may be) affected.

The dynamic re-filtering requires full data persistence (in the general settings), and the bar labeling only works if “Re-color Bars” is selected (in the bar settings).

For schedulers and schedule reviewers, the new Project Logic Checker provides an action-focused basic schedule health check functionality that can be leveraged off the various logic tracers included in the tool. There is no fancy dashboard and no pass/fail metrics based on odd ratios. For now I think I prefer it that way.

Macro for Tracing, Filtering, and Sorting Task Paths in Microsoft Project

Here are three macros (collectively called QuickTrace) to display the logical predecessors or successors (or both) of the selected task – filtering out all others – and sorted by logical path. The filter can be limited to show all logic or only “driving” logic. There is also a highlight-only option.

With the apparent demise of Mike Dahlgren’s site, masamiki.com, his “Trace” macro seems to no longer be generally available. (It’s also a violation of his site’s terms of use to re-distribute code that was obtained there.) My entry on Listing Driving Predecessors has been getting a lot of traffic from people who (I suspect) are trying to find a variation of Trace. In response to a question over at MPUG today, I decided to write up something – what I call QuickTrace – to generate similar output for sharing. It is after all less than a hundred lines of code. [Note: The code here works for all modern – i.e. 2007 and later – versions of MSP. If you are already using the “Task Path” bar styles in MSP 2013+ and are looking for a compatible filter, then have a look at my other article: Macro for Filtering based on “Task Path” in Microsoft Project.]

For determining driving relationships, QuickTrace relies on MSP’s “StartDriver” task object, the basis of the Task Inspector pane (and the “Task Path” Driving Predecessors and Driven Successors bar styles in MSP 2013+). This is a substantial improvement over the original Trace macro, which used Free Slack as the driving indicator. Still, I’ve found StartDriver to be unreliable in the presence of non-FS relationships (See here.) BPC Logic Filter (our MSP Add-In) instead identifies driving relationships directly by computing and examining relationship free floats – quite a bit more involved.

[Jan’19 Edit: QuickTrace also relies on recursion (a sort of repeated self-cloning process), and this makes it susceptible to crashing if the path length (i.e. the number of tasks in sequence) is too long. In MSP 2010, I’ve analyzed path lengths a bit over 4,000 tasks before crashing. The same analysis in MSP 2016 leads to a crash after only 700 tasks.

Version 1.5 of BPC Logic Filter now includes a QuickTrace option.

This implements the same recursive tracing algorithm that I’ve included in the macro code. It’s blazing fast, and its results are perfectly aligned with the Task Path bar styles of MSP 2013+, no matter how flawed. It also handles much longer path lengths (just under 8,000 tasks in MSP 2016) before running out of memory.]

Here’s the code. There are basically three front-end macros that you can assign buttons or hot keys to, one for predecessor chains, one for successor chains, and one for both. (Using the last one can make the resulting path sort a little jumbled, so I made re-sorting optional.) These call the other procedures to a) collect user input; b) clear existing values in the Flag4 and Number5 fields; c) recursively run through the chains of related tasks and and mark them using those fields; d) apply the filter and sort using those fields; and e) display a message box summarizing the filter/highlighting. Note, this is provided as-is and is not supported by anyone. I have not taken the time to accommodate every possible situation and won’t be doing so in the future. If you are new to vba, please google around a bit before asking questions that are already answered somewhere else – that includes, “how do I install this and make it work?” (Short answer: copy and paste the entire block into a new module in the visual basic editor. Then add the three front-end macros to a custom group on one or more of your ribbon tabs.)

'QuickTrace Module
'Coded by T.Boyle, PE, PSP on 16Mar'17 [25Sep'18 edits - to allow highlighting, to provide a descriptive message box
'   after running, and to streamline the code.]  This Module is intended to trace logical paths from the selected task
'   to all of its predecessors or successors, then show only related tasks.  Tasks are sorted in the order of analysis,
'   which generally corresponds to identified logical "paths".
'CAVEATS:
'   1. This code WILL OVER-WRITE fields FLAG4 and NUMBER5.  Make sure these fields are not needed before running.  Otherwise,
'      edit the code to use different fields, as shown below.
'   2. This code relies on the StartDriver object for defining driving path logic.  It may not always be reliable for non FS
'      relationships.
'   3. Install all code into a new module, with "QuickTrace Module" above as the top line.
'   4. Assign buttons or hotkeys to the first three procedures only (the others are called by these three):
        'a. CallQTraceP() - Traces predecessors.
        'b. CallQTraceS() - Traces successors.
        'c. CallQTraceB() - Traces both predecessors and successors (Added 15Nov'17)
'
 
Option Explicit
Private Cnt As Long, Driv As Boolean, HL As Boolean, ShowSums As Boolean, Tsel As Task, DirGlob As String
 
Sub CallQTraceP()
    'This procedure finds, marks, filters, and sorts predecessors of the selected task.
    'Run this directly using a button or hot key
     
    Cnt = 0
    DirGlob = "P"
        
    ClearFields
    CollectInput
    'Run Trace from Selected cell
    Call QTrace(Tsel, "P")
    Call Filter("P")
 
End Sub
 
Sub CallQTraceS()
    'This procedure finds, marks, filters, and sorts successors of the selected task.
    'Run this directly using a button or hot key
     
    Cnt = 0
    DirGlob = "S"
        
    ClearFields
    CollectInput
    'Run Trace from Selected cell
    Call QTrace(Tsel, "S")
    Call Filter("S")
 
End Sub
 
Sub CallQTraceB()
    'This procedure finds, marks, filters, and sorts both predecessors and successors of the selected task.
    'Run this directly using a button or hot key
     
    Cnt = 0
    DirGlob = "B"
        
    ClearFields
    CollectInput
    'Run Trace from Selected cell
    Call QTrace(Tsel, "P")
    Call QTrace(Tsel, "S")
    Call Filter("P")
 
End Sub
 
Sub QTrace(ByRef t As Task, ByVal dir As String)
    'This procedure marks a task (as related) and calls itself for each related predecessor or successor.
    'This procedure is called by another procedure.
     
    Dim d As TaskDependency
    Dim ds As TaskDependency
     
    'Mark this task as related
    Cnt = Cnt + 1
    '''''''''''''''''''''''''''''''''''''''''''''Edit Fields Flag4 and Number5 as Needed'''''''''''''''''''''''''''''''''''''''''
    t.Flag4 = True
    t.Number5 = Cnt
    '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
     
    'Recurse to next dependency
    If Driv Then
        If dir = "P" Then
            For Each d In t.StartDriver.PredecessorDrivers
                Call QTrace(d.From, "P")
            Next d
        Else 'i.e. dir="S"
            For Each ds In t.TaskDependencies
                If ds.From = t Then
                    For Each d In ds.To.StartDriver.PredecessorDrivers
                        If d.From = t Then Call QTrace(d.To, "S")
                    Next d
                End If
            Next ds
        End If
    Else
        For Each d In t.TaskDependencies
            If dir = "P" And d.To = t Then Call QTrace(d.From, "P")
            If dir = "S" And d.From = t Then Call QTrace(d.To, "S")
        Next d
    End If
End Sub
 
Sub CollectInput()
    'This procedure collects user input.
    'This procedure is called by another procedure.

    Driv = False
    HL = False
    ShowSums = False
    
    Set Tsel = ActiveCell.Task
    If MsgBox("Driving Path only?", vbYesNo) = vbYes Then Driv = True
    If MsgBox("Highlight only?", vbYesNo) = vbYes Then
        HL = True
    Else
        If MsgBox("Show Summary Tasks?", vbYesNo) = vbYes Then ShowSums = True
    End If

End Sub
Sub ClearFields()
    'This procedure runs through the tasks of the active project and clears two selected fields for use.
    'This procedure is called by another procedure.
     
    Dim t As Task
    'Clear Fields
    For Each t In ActiveProject.Tasks
        If Not t Is Nothing Then
    '''''''''''''''''''''''''''''''''''''''''''''Edit Fields Flag4 and Number5 as Needed'''''''''''''''''''''''''''''''''''''''''
            t.Flag4 = False
            t.Number5 = 0
    '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
        End If
    Next t
End Sub
 
Sub Filter(ByVal dir As String)
    'This procedure creates and applies a filter to show only related tasks.
    'This procedure is called by another procedure.
     
            '''''''''''''''''''''''''''''''''''''''''''''Edit Field Flag4 as Needed'''''''''''''''''''''''''''''''''''''''''
            FilterEdit Name:="Flag4", TaskFilter:=True, Create:=True, _
                OverwriteExisting:=True, FieldName:="Flag4", Test:="equals", _
                Value:="Yes", ShowInMenu:=True, ShowSummaryTasks:=ShowSums
            FilterApply Name:="Flag4", Highlight:=HL
            '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
        
        If ShowSums Then '(HL is False)
            'Sort by path order
            If MsgBox("Resort to show paths?", vbYesNo) = vbYes Then
            '''''''''''''''''''''''''''''''''''''''''''''Edit Field Number5 as Needed'''''''''''''''''''''''''''''''''''''''''
                If dir = "P" Then Sort Key1:="Number5", Ascending1:=False, Renumber:=False, Outline:=True
                If dir = "S" Then Sort Key1:="Number5", Ascending1:=True, Renumber:=False, Outline:=True
            '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
            End If
        Else '(ShowSums is False and HL may be true or false)
            If Not HL Then
            'Sort by path order
                If MsgBox("Resort to show paths?", vbYesNo) = vbYes Then
            '''''''''''''''''''''''''''''''''''''''''''''Edit Field Number5 as Needed'''''''''''''''''''''''''''''''''''''''''
                    If dir = "P" Then Sort Key1:="Number5", Ascending1:=False, Renumber:=False, Outline:=False
                    If dir = "S" Then Sort Key1:="Number5", Ascending1:=True, Renumber:=False, Outline:=False
            '''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
                End If
            End If
        End If
        EditGoTo ID:=Tsel.ID
        FilterBox
End Sub
        
Sub FilterBox()
    'This procedure creates and displays a message box describing the filter/highlight basis.
    'This procedure is called by another procedure.
    Dim Msg As String
    
    If HL Then
        Msg = "Highlighting "
    Else
        Msg = "Filtering for "
    End If
    
    Select Case DirGlob
        Case "P"
            If Driv Then Msg = Msg & "driving "
            Msg = Msg & "predecessors "
        Case "S"
            If Driv Then Msg = Msg & "driven "
            Msg = Msg & "successors "
        Case "B"
            If Driv Then Msg = Msg & "driving & driven "
            Msg = Msg & "predecessors & successors "
    End Select
    
    Msg = Msg & "of task " & Tsel.ID & ": " & Tsel.Name & " (inclusive)"
    MsgBox Msg
    
End Sub

[Aug’18 Edit:] One of the commenters sent an example of a schedule where the macro includes in the driving path to project completion two tasks that are in fact neither critical nor driving . As shown below, the Task Path functionality is used to highlight the “Driving Predecessors” to Task 13 (orange bars).

Tasks 21 and 22 are included in the Task Path highlighting, and they are also flagged as part of the Driving Path (to Task 13) by the QuickTrace macros. This is because MSP has marked Task 22 as the StartDriver predecessor for Task 26. As a manually-scheduled task, however, Task 26 really has NO StartDriver predecessor, and the reference to Task 22 is incorrect. Neither the macro nor the Task Path function has been adapted to account for this. (BPC Logic Filter correctly excludes these non-driving tasks, and MSP marks them as non-critical because they possess positive Total Slack.)

Troubleshooting Circular Task Relationships with BPC Logic Filter

Planners attempting to build complex project schedules in Microsoft Project will typically come across the circular logic warning at some point when trying to link tasks.

In general, most such messages come from assigning logic to summary tasks, which experienced schedulers don’t do.

When an experienced scheduler encounters the circular logic warning, it often means that he has made an earlier error in the logic that is only now being detected as the loop is closed. For example, a normal construction “fragnet” for concrete structures may include the following task sequence: Form -> Pour -> Finish -> Cure – > Strip(forms), repeated over and over for different structures on the project. If I get the warning when trying to impose one of these obvious links – say from Pour to Finish, then I know that Pour and Finish are already connected. I have to find the logical error in that path of task connections.

Fortunately, BPC Logic Filter includes a little feature that’s been variously referred to as “Bounded Network Analysis,” “Truncated Logic Tracing,” and “Logic Tracing to Target.” It finds all the connections between any two tasks in the project and filters out all the others. This makes finding the error that much easier. The figure below highlights the selected task (Form3) in yellow and the target task (Pour3) in orange. In the example, I can trace the problem linking Form3 and Pour3 to a “dummy string” of tasks that was inserted between Cure3 and Cure2.

Early last year I wrote about a method for finding the connections between two arbitrary activities in a CPM schedule. Most of that post was aimed at using the circular logic error handler in Oracle Primavera P6 to accomplish the objective. Obviously, this turns that method around.