Hard and Soft Dependencies

<A beer in London – £4.30!>

Most problems (or opportunities of course) arise from customer queries; really, if it wasn’t for you guys keeping me on my toes I would just spend everyday cycling….  Some days I combine Project and Project Server with cycling….

brompton

Anyway, I digress; one of my customers wanted a way to differentiate between mandatory and discretionary (or hard and soft) dependencies.  If you are not sure of the difference, they have a quick look here

For my customer, the idea was that they wanted to be able to enter both hard and soft dependencies, and then implement and remove the soft logic links at their own discretion. So it gives them the ability to implement “what if” scenarios if the schedule got a little “tight”, allowing them to remove the soft dependencies effectively crashing the project.  Alas Project doesn’t allow use to add a flag to the dependency type, and so I figured the following work around.  Please note that this is in early developmental stages and so feel free to use this code; and if you improve on it, please let me know; and if you use it, please credit me (oh, and buy me a beer when you see me).

Step 1.

Create a text custom fields, called soft predecessor(s) unique ID using Text1; if you cannot use this field, choose another one and modify the VBA accordingly.  Note in the screen shot is shows that I have changed Text2 also; in the end I didn’t use this.

 

image

Step 2.

In your favourite table, add in the columns, unique ID and the Soft predecessor(s) unique ID.  We need to utilise the unique task ID, as the usual ID field can change when tasks are moved/inserted etc.  Typically I add these to the left of the predecessor column (which I typically move to the left of the task name anyway – the order isn’t important, but the visibility is).

image

Step 3.

Add the following VBA code into a module or macro in your favourite project client….  note that there are two procedures AddSoftPredecessors and RemoveSoftPredecessors.  Their individual use should be fairly self explanatory.

Sub AddSoftPredecessors()
‘ 07/03/2014 Ben Howard – ben@applepark.co.uk www.applepark.co.uk/ben-howard-blog

Dim TskID1, TskID2, TskID3 As Long
Dim Tsks As Tasks
Dim Tsk As Task

SelectAll
Set Tsks = ActiveProject.Tasks

For Each Tsk In Tsks

    ‘ check to see if a task exists
    If Not Tsk Is Nothing Then
        ‘ MsgBox (Tsk.Name)
        ‘ Tsk.Text2 = Tsk.UniqueIDPredecessors
        ‘ ConCatPreds = string   concat(tsk.UniqueIDPredecessors, tsk.Text1)
        If Tsk.Text1 <> "" Then
            ‘ MsgBox (Tsk.Name & " has a predecessor")
            ‘ Tsk.Text2 = Tsk.UniqueIDPredecessors & "," & Tsk.Text1
            If Tsk.UniqueIDPredecessors <> "" Then
                tempstr = Tsk.UniqueIDPredecessors & "," & Tsk.Text1
            Else
                tempstr = Tsk.Text1
            ‘ MsgBox (Tsk.Name & " " & tempstr)
            End If
            Tsk.UniqueIDPredecessors = tempstr
        Else
            ‘ MsgBox (Tsk.Name & " has no predecessor")
        End If
    End If
Next Tsk

End Sub

Sub RemoveSoftPredecessors()
‘ 07/03/2014 Ben Howard – ben@applepark.co.uk www.applepark.co.uk/ben-howard-blog

Dim Tsks As Tasks
Dim Tsk As Task

SelectAll
Set Tsks = ActiveProject.Tasks

For Each Tsk In Tsks

    ‘ check to see if a task exists
    If Not Tsk Is Nothing Then
        ‘ check to see if we have both hard predecessors and soft predecessors
        If (Tsk.UniqueIDPredecessors <> "") And (Tsk.Text1 <> "") Then
            ‘ MsgBox (Tsk.Name & " has this chacter " & Tsk.Text1 & " at position " & InStr(Tsk.UniqueIDPredecessors, Tsk.Text1) & " in the Predecessors")
            If InStr(Tsk.UniqueIDPredecessors, Tsk.Text1) >= 0 Then
                ‘we know that some part of the string is matched
                ‘MsgBox (Tsk.Name & " some match")
                ‘MsgBox ("Unique Predecessor length of " & Tsk.Name & "is " & Len(Tsk.UniqueIDPredecessors))
                ‘Find out if the next character is a delimiter
                nextchar = Mid(Tsk.UniqueIDPredecessors, InStr(Tsk.UniqueIDPredecessors, Tsk.Text1) + 1, 1)
                ‘ MsgBox ("next char " & nextchar)
                newstr = Replace(Tsk.UniqueIDPredecessors, Tsk.Text1 & nextchar, "")
                ‘ check if there is a ‘ as the last character
                If Len(newstr) > 0 And ((InStrRev(newstr, ",") = Len(newstr))) Then
                    ‘MsgBox ("we have a comma as the last char")
                    newstr = Left(newstr, Len(newstr) – 1)
                End If
                ‘MsgBox ("NewStr " & newstr)
                Tsk.UniqueIDPredecessors = newstr
            Else
                ‘MsgBox (Tsk.Name & " no match")
            End If
            ‘ create a new string that removes duplicates from the two strings
        End If
    End If
Next Tsk

End Sub

Step 4.

Whilst we are playing around with adding the VBA/Macros, we might as well assign a couple of buttons to them in the ribbon.  I’ll just include the final screen shot here.  If you aren’t sure how to customise the ribbon, then buy the book!

image

Step 5.

Enter your predecessors and dependencies as usually would.  These will become your “hard” predecessors.  Project schedules and accordingly based upon these dependencies and the existing constraints and task mode(s) within the project.  Notice that task T2 has hard predecessors of both T3 and T1.

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Step 6.

Now comes the “fun” part.  In the schedule, for each task, enter the soft predecessor unique ID(s).  In the UK, these are separated by a comma; if your regional settings are different, you’ll need to modify the VBA.  For Task T3, I am going to create a “soft” predecessor of task T1.

image

Step 7.

To apply this “soft” dependency and see the effect on the schedule, click on the Add Soft Predecessors button to run the VBA.

Notice how the Unique ID Predecessor (the hard predecessor) of task T3 now equals the Soft predecessor ID, and the consequence that it this then has on the rest of the schedule (task t3 and Task T4 have both moved).

image

Step 8.

You can remove the effects of the soft dependency by clicking on the Remove Soft Predecessors button.

If you want to see a video of this working, click here and look for the SoftLinksMacro video file.

Enjoy,  Ben.

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