W6_HMIP_Fix Out of Sequence Activities of Garuda AACE 2015 Schedule

  1. Problem Definition

During updating project Garuda AACE 2015 project schedule on weekly basis, we found that there was several out of sequence activities during updating garuda AACE 2015 every week. We afraid that our schedule did not reflect the accurate schedule.

Figure 1 : Out of sequence activities

Figure 1 : Out of sequence activities

  1. Identify the Feasible Alternative

Therefore, we found that we need to use several alternatives on addressing out-of-sequence activities, unless the schedule not reflect the accurate schedule. Rescheduling activities may require adjusting network logic to explain why an activity did not start as planned, particularly if any of its successors have started or been completed. An activity’s starting before its predecessor activity has completed is out-of-sequence progress. Out of-sequence progress is common and should be expected, because some activity managers know they can safely start their activities, sometimes challenging their predecessor activity teams to speed up. When out-of-sequence progress occurs, managers and schedulers may choose to retain or override the existing network logic.

The situation that must be addressed when activities are performed out-of sequence in a network is whether the logic needs revision or simply that an anomaly has occurred that should not require any revision.

  1. Development of the outcome for Alternatives

Out-of-Sequence Activities :

An out of sequence activity is an activity that is worked in an order other than how it was originally planned. When you build a schedule with relationships, you’re not only doing so to enable the tool you’re using to calculate dates, you defining the sequencing of those activities involved in the relationship.

One of the primary goals of effective schedule management is to ensure that the planned schedule is periodically updated to reflect the actual progress of the work. Unless that updating procedure includes appropriately addressing out-of-sequence work, the schedule may become a poor reflection of reality and an unusable tool for planning. Out-of-sequence progress occurs when a series of activities are not performed as they were originally planned to be performed. This situation can cause detrimental consequences to the schedule if the scheduler does not carefully and appropriately respond to the changes presented by the actual conditions on the project.

There were several methods in on addressing out of sequence activities :

  1. Retained Logic
  2. Progress Override
  3. Fixing out of sequence activities manually
  1. Selection of Criteria

Retained logic and progress override are options in scheduling software that must be properly set before updating the status of the schedule. Each approach represents a different philosophy on how to manage unexpected developments in the project, and they can have vastly different effects on forecasted dates. It is recommended that the scheduler and activity leads examine each instance of out-of-sequence progress to determine the correct response case by case. While out-of sequence activities are common, they should nonetheless be reported, and an analysis of the effect on key milestone dates is recommended before out of sequence activities are formally addressed. Out-of sequence activities may represent risk or potential rework, because knowledge or products from the predecessor activity were not complete and available to the successor activity.

  1. Analysis and Comparison of the Alternatives
    1. Retained Logic – Selection of the Retained Logic option will allow the affected activity to start early, but schedule its completion in accordance with the network logic. The activity will not be allowed to complete until all its predecessors are completed, and the original duration is satisfied.
    2. Progress Override – Selecting Progress Override will treat the activity with out-of-sequence progress as if it has no predecessors so it can continue without being affected by its incomplete
    3. Fix out of sequence manually – This method was manually fixing all out sequence activities one by one of all activities and relationships.
  1. Selection of the Preferred Alternative

Before selecting alternative, we need to do schedule Verifying Status Updates and Schedule Integrity. Once the schedule has been statused , management should review the inputs to verify the updates and assess the effect on the plan. The schedule should be reviewed to ensure the following:

  • All activities completed prior to the status date represent finished work and therefore should have actual start and finish dates. They should be statused as 100 percent complete with actual durations or actual work values.
  • In-progress activities should have an actual start date and all work scheduled before the status date is expressed as actual duration or actual effort. All remaining work should be scheduled beyond the status date.
  • Activities planned beyond the status date represent future activities and therefore should not have actual start or actual finish dates. They also should not have actual duration or work values.
  • Out-of-sequence activities are addressed purposefully and case by case through either retained logic or progress override.
  • Schedule recalculations from changes in estimated work, assigned resources, or duration are verified to ensure meaningful and accurate calculations.
  • Resource assignments are assessed for the coming period, and assignments for delayed or out-of-sequence activities are reevaluated for potential overallocations. In addition, resource calendars should be updated to reflect current availability.
  • Date constraints are revisited and removed if possible. In particular, soft constraints should be removed if they can no longer affect an activity’s start or finish date.
  • At least one in-progress activity is critical. If not, it is most likely that date constraints or external dependencies are separating subsequent from the in-progress activities. Such breaks in the critical or longest path represent weak or incomplete logic, causing a lack of credibility in the identity of the path and the schedule dates.

Schedule integrity should also be assessed in the schedule update process. Verifying the integrity of the schedule after each update will ensure that the schedule remains reliable after activities are added, removed, broken down into smaller activities, or sequenced differently from the last period.

  1. Using Retained Logic :

Retained Logic – The data date and all logical relationships are considered and out-of-sequence work is automatically suspended until all logically preceding work is complete.

Figure 2a : Retained Logic Option in Primavera

Figure 2a : Retained Logic Option in Primavera

2. Using Progress Overide :

Progress Override – The data date is considered but any predecessor relationship to the out-of sequence activity is completely ignored by the CPM calculations. Note that this does not prevent the software from displaying such relationships as if they were still was in effect.

Figure 2b : Progress Override Option in Primavera

Figure 2b : Progress Override Option in Primavera

After update schedule using retained logic and progress override, we still find the same out of sequence with before the schedule updated in Figure 1 :

Figure 1 : Out of sequence activities

Figure 1 : Out of sequence activities

3. Using fix out of sequence activities manually :

Than we do the final approach by fixing out of sequence activities manually one by one in their relationships :

Figure 3 : Fixing out of sequence manually before change relationship

Figure 3 : Fixing out of sequence manually before change relationship

Figure 4 : Fixing out of sequence manually after change relationship

Figure 4 : Fixing out of sequence manually after change relationship

Figure 5 : Out of Sequence activities after updated

Figure 5 : Out of Sequence activities after updated

We didn’t find activity : Submit Blog Posting Week 4 in out of sequence activities after the relationship change to Start – Start and the schedule updated. We will do for all of activity one by one manually by updating their relationships.

  1. Performance Monitoring and the Post Evaluation of Result

We would all agree that you are not always going to execute work exactly as you planned, but the question is what should you do about it when it shows up as out of sequence activities? The answer depends on why you are executing the tasks out of sequence and why the assumption (remember a relationship is an assumption of how you plan to execute the work) is no longer valid. There are a variety of reasons why it makes good project management sense to execute tasks out of sequence, some of which are listed in the paragraph above. If that happens, you need to be aware of it and also understand the implications of doing so.

When an out of sequence activity is identified you need to go back to the original assumptions used when the plan was put in place. Remember, the original relationship represents an assumption about how the work will be executed. Key here is, does changing the way the tasks are executed introduce risk into your plan.

If your original plan called for finishing all of the development before you started testing then you could probably rationalize starting the submit blog posting week 4 before the submit blog posting week 3 was complete. You could start submit blog posting week 4 without waiting blog posting week 3 to be complete. If your submit blog posting 3 than the reference is not as required, you might have a problem.

You will need to look at each situation and determine if new logic is needed or if you should stop work on the out of sequence activity until the original logic can be honored. So it’s not necessarily bad that you have something out-of-sequence, it’s just bad if you do not know it is occurring and do not take the necessary steps to deal with the situation.

The Out-Of-Sequence metric, along with metrics like relationship validations, bottleneck identification, risk hot spots, task density, duration validation and others are all valuable inputs to maintaining a quality, reliable schedule. Reviewing these metrics regularly throughout the life of a project ensures your schedule will provide you and the project stakeholders with the most relevant information to act on, and knowing is half the battle.

References :

  1. Humphreys, G.C. (2011). Project Management Using Earned Value Third Edition. Humphreys & Associates, Inc, Chapter 13 Page 280.
  2. Schedule Assessment Guide, pp.127, 130, 131.
  3. AACE International Standard Practice No. 49R-06 Identifying the Critical Path pp 6.
  4. Wagner, Ralph. Scheduling Best Practice pp 2 – 4. Retrieved from http://warnercon.com/wp-content/uploads/2012/07/Article-9-Handling-Out-of-Sequence-Progress1.pdf
  5. Tensix Consulting. What Do You Do About Out Of Sequence Activities?. Retrieved from http://tensix.com/2015/02/what-do-you-do-about-out-of-sequence-activities/
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2 Responses to W6_HMIP_Fix Out of Sequence Activities of Garuda AACE 2015 Schedule

  1. drpdg says:

    Nice job, Pak Hery…….

    About the only detail you missed addressing specifically is what happens to the earned value calculations when you use progress over-ride or retained logic……

    Not sure of they fixed it in P6 but in P3, if you didn’t fix out of sequence progress, you lost all the earned value for that string of activities……

    But the bottom line remains- the schedule should at all times reflect as realistically as possible not only what the original plan WAS (baseline) but what we are actually doing on the job, which is why we should always create a baseline and then from time to time compare what is actually being done (including fixing out of sequence progress) against the original plan and at some point in time, when what is actually happening is significantly different than what was planned, we have to REBASELINE and start again fresh….

    Good job on your analysis but think about what I explained above….

    Dr. PDG, Jakarta


  2. Pingback: W11_IN_Alternatives Handling Out-of-Sequence Schedule Activity – Pearl AACE 2017

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