Design-Build Project Schedule Development and Management - Design-Build for Water and Wastewater Projects - page 243

The process constantly loops around the define-measure-detect-predict-act time manage-
ment cycle.
The define stage of the cycle establishes the operational schedule, baseline or updated.
Hence, there is an explicit bidirectional interlocking feedback mechanism between the
scheduling and controlling processes.
The measure stage is the assessment and reporting of progress. Schedule tasks need
to be updated with respect to their actual start, percent complete, remaining duration,
and actual finish. Assessing the percent complete for each task is necessary to gain a true
understanding of the status of the project, as of a given date. Actual units in place is the
most reliable method for assessing the percent complete for a give task. Taking shortcuts
by using a task's days elapsed or cost incurred can be misleading and disastrous. Estimating
a task's remaining duration should be based on units yet to be installed and on an actual
productivity that was achieved through the data to date.
The detect stage involves comparing actual and planned achievements to identify
deviations. The earned value methodology is ideal for performing the comparison. The
budgeted cost of work scheduled (BCWS), the budgeted cost of work performed (BCWP),
and the actual cost of work performed (ACWP) are indicators that measure the status of
the project with respect to the budget and time dimensions. These indicators quantify the
effect of delays, disruptions, and changes.
The predict stage estimates the completion dates and costs based on the achieved
progress and remaining work. The earned value methodology is, once again, ideal for per-
forming such estimates. Choosing between retained logic or progress override reschedul-
ing modes is a key decision directly affecting the estimates at completion and needs to be
explicitly disclosed and explained to all who use the scheduling information.
The act stage involves planning and implementing corrective actions by discussing
the project status with all major stakeholders, discussing mitigating steps to recover time,
negotiating change orders, and negotiating excusable delays. Updating the operational
schedule with these corrective actions is necessary to develop a new baseline schedule to
be used on the next iteration of the time management cycle. When the impact of changes
is extreme, it is necessary to update the planning goals, intent, and objectives. As a result,
there is an inherent feedback mechanism between the controlling and planning processes.
A product of systematic looping through the define-measure-detect-predict-act time
management cycle is a contemporaneously developed as-built schedule (i.e., a historical
record of events and progress).
SCHEDULE IMPACT ANALYSIS
The overall outcome from a systematic and standardized schedule impact analysis is to
resolve claims for additional time, so as to avoid unresolved claims that tend to result
in disputes (Wickwire et al. 2003; Keane and Caletka 2008). Disputes are the result of
mismanaged claims for additional time from delayed events to the project. Because of
the financial impacts of project delays for both owners and design-builders, time impact
analyses of changes should be a common practice in the execution of DB projects.
Once claims become disputes, they are much more expensive to resolve because invari-
ably these require adjudication by a third party (i.e., arbitration, dispute review boards,
and/or litigation).