Schedule Updating and Project Control - Construction Project Scheduling and Control - page 165

after the start of the project, 6 days' worth of work is done on activity A (remaining
duration = 4) and 2 days' worth of work is done on activity B (remaining duration
= 6). Should we choose Retained Logic (the default value, Figure 7.3b) or Progress
Override (Figure 7.3c)? The decision between the two choices may mean not only the
difference in the project's completion date but perhaps also the start and finish dates
of some succeeding activities. In this example, the decision means a 4-day difference in
the completion date of activity B, and possibly the entire project. Oracle Primavera P6
also gives a third option: actual dates. This option works only if the scheduler assigns
an actual start date that is after the data date. 2
Auto-Updating
Some software scheduling programs offer an option for automated updating.
Although this option makes updating easy and saves time, a potential danger exists.
Along with such options comes the assumption that everything that was supposed to
have happened, between the last and current updates, has happened—on the planned
dates and within the planned budget and resources. This assumption may be true
in most but not all cases. The potential danger is that the scheduler will become
accustomed to using this convenient tool and use it all the time. The scheduler should
exercise extreme caution in using such automated procedures.
Updating Schedules and Pay Requests
In many cases, project updating is tied to payment requests (pay requests , for short).
The subject of pay requests is a broad one that is discussed in detail in other project
management topics. What concerns us in this chapter is how pay requests are tied to
schedule updating. In general, a pay request is a document submitted by the contractor
(using his or her own form, the owner's form, the American Institute of Architects
Document G702, or other form) to the owner, asking for payment for work actually
performed (whether finished or not) during the period since the last pay request.
Materials stored on-site but not yet installed are generally ineligible for inclusion in
pay requests, unless the contract allows for such payment. Typically, the owner verifies
the amounts in the pay request (quantities and unit prices) and then, after approving
it, issues a payment to the contractor that is equal to the approved amount minus any
retainage . 3 Pay requests are usually done at the end of each month or billing period.
2 It is like the past in the future! The author does not like such a practice, as it may lead to reporting false
information if that event does not occur on the specified date.
3 Retainage (also called retention ) is a portion of the eligible progress payment that is held back by the owner
until the contractor fulfills his or her contractual obligations. The contract usually specifies the amount and
conditions of a retainage.