Overall Project Schedule at FEP-1 Stage
As mentioned in the article of Rolling-Wave Planning, the cost estimate at this stage will be a class 5
estimate as defined by the AACE Recommended Practice 104R-19. This
estimate usually has an accuracy range of minus 50% to plus 100%. The
schedule duration calculated for the project will follow the same steps.
The definition of the project duration at this stage is based most of
the time on benchmarking. However, unlike the cost estimate, it is not
the best way to calculate the total cycle time or the execution duration
of the project. Project drivers, execution constraints, and project
risks are better in making a duration prediction. The planner/schedule
will put these factors together on a simple one-page Gantt chart to
study their impact on each other and develop a Level-1 schedule that
corresponds to Class 5 estimate. These factors will be covered in the
following paragraphs then examples of Level 1 schedules will be shown.
Project Drivers
Project drivers are those factors that motivate and guide the
development of a project during its lifetime. They can be internal, such
as financial constraints, deadlines, customer and supplier expectations,
or external, like market trends, legal and regulatory requirements,
labor and materials costs etc. These drivers are combined to define the scope
of the project. Industrial projects have many drivers mainly defined by
the market, the maintainability of the plant, and the protection of the
environment. The latter is mostly defined by governmental regulations or
the desire of the owner company to contribute positively to the quality
of the environment.
High-level scope-breakdown (WBS)
A Work Breakdown Structure (WBS) is an approach used to divide an
industrial project into smaller, more manageable components. It is
typically hierarchical in nature, showing the overall project at the top
level, with subsequent levels representing further divisions of the
project. The WBS helps identify all of the individual components and
tasks that need to be completed for the successful completion of the
project. When reaching to the smallest manageable component, it is
possible to start adding tasks that reflect the execution strategy of
those components. Each component is assigned a unique identifier to aid
in planning tasks and resources, and to ensure that all tasks have been
considered in the planning phase. A WBS is also used to assign
responsibility and accountability, plan project duration and schedule,
and to estimate project costs.
During the early planning phase, namely the first stage of front end planning (FEP-1), the high level
WBS only is needed. Below, there is an example for high level WBS for an
industrial boiler used for power generation.
The Conceptual Schedule
The plan or the schedule will be built as follows:
The total duration of the project will be calculated in a similar
manner like the estimate based on benchmarking the project to
completed projects with similar production capacity. The execution
duration will be also calculated the same way.
The schedule of the FEP-1 Phase which is usually a few procedural
steps to complete FEP-1 will be a detailed Level 3 schedule. This
schedule usually fits in one or two pages.
The schedule for FEP-2 will be a top-down Level 2 schedule to show
some details of the work to be performed during the FEP-2 Phase.
The schedule for FEP-3, Execution, and Startup Phases will be a
Level 1 schedules to show the main milestones, key scope breakdown
areas,
Project constraints can be shown in a separate section or made clear
in their subsequent area. Examples of project constraints are the
permits, availability of resources, equipment tie-ins, very long
lead items, etc.
This schedule is not a detailed critical path schedule. It should be
treated as a planning tool to indicate the initial criticality of major
construction areas, the impact of potential risks that might happen
during the project execution, and how to react to project constraints.
The figure below shows the one-pager schedule for the boiler project.
The schedule is grouped by the WBS mentioned above. The general area
contains milestones, FEP-2, FEP-3, and the clearly defined constrains.
The rest of the schedule is displaying the engineering, procurement, and
fabrication (or construction) of each of the scope areas.
Looking at this schedule, it can be found that the "Environmental
Permit" is not the only constraint. Yes, it represents a constrain on
the startup of the boiler especially with the unknowns associated with
it. However, the "Furnaces" area requires longer engineering and longer
construction than other areas. Also, the "Control Room" procurement is
very long with risks of delivery on time. This very long lead item
represents another constraint on the project.
The project management team (PMT) should work on understanding the
factors impacting the date of boiler startup and work on minimizing the
risk of overruns. For example, the "Control Room" procurement can be
placed and awarded to the selected vendor during the FEP-3 stage.
Another example is accelerating the engineering required to order the
"Environmental Permit". For the "Furnace" area, it needs to have a very
high priority by the engineering and fabrication teams. Engineering and
construction can be carefully overlapped for this area to minimize the
risks of extending its duration which would impact the mechanical
completion date.
In conclusion, the initial or conceptual schedule needs to describe the:
Scope
Constraints
Execution Strategy
The benefit of the conceptual schedule is to plan the timing and
priorities for the execution phase. It is not a real critical path
schedule. It is a planning tool that reflects the reality of the
project. The promise date produced by this conceptual schedule is more
realistic than a date driven by benchmarking only. This approach
incapsulates the reality of the project, its drivers, and constraints
into the calculation of the promise date. Benchmarking is needed to
start but it is not enough to conclude a completion date of a project.