Production Management
Conventional, CPM based project management deals mainly with the
activities that need to be carried out in order to complete a given
project. Production management deals with the physical output
generated by those activities.
Thus, an activity plan shows the activities that will be under
way, day by day or week by week during the project. A production
plan shows the level of physical output that must be generated day
by day or week by week throughout the project in order to complete
the job on time.
The C3 Production Management project process is illustrated in the
diagram above. In broad terms, it works as follows:
- The starting point for the production plan is a detailed
list of the components of the building in question, taken off
from the drawings in the form of a 'smart' bill of quantities.
Each component is identified according to a catalogue of Unique
Component Codes and its location and quantity are recorded.
- Each component or group of components is then allocated to one
or more construction packages. The man-hours and / or monetary cost
of installing each component are assigned according to the package
schedule of rates. In this way the 'planned value' of each installed
component, thus of the package as a whole, is established - before
construction gets under way.
- The key point about this step is that it establishes the 'value'
of all the various components of the building in common units:
man-hours or monetary cost. This is the basis on which all
subsequent calculations are carried out. Reducing everything to a
common basis of value enables comparison and aggregation of
completely different types of operation, brickwork pipework for
example, over time on any given project, and importantly across
different projects.
- The Planned Progress curve for the package in question is
generated by spreading the man-hours or costs across the package, or
sub-package, duration according to a simple production function.
- When work gets under way the actual installation of individual
components is recorded, as it happens, preferably on a continuous,
daily basis. Every time the contractor completes the installation of
a component he 'earns' the man-hour or monetary value of that
component.
- This information is added to the production plan generate the
'Earned value' of the work performed. The actual percent complete of
the package can then be calculated as the ratio of the earned value
to the initial total planned man-hour or monetary value of the
package. This is plotted as the Actual Progress curve. Packages can
be grouped and totalled in the same way to give group and overall
project values and curves.
- It is highly desirable that when the fact of a component
installation is recorded, the man-hours used in its installation are
also noted. This enables labour usage, productivity and
effectiveness to be monitored and managed.
In general the information required to drive Production
Management is neither new nor particularly different. 'Dumb bills of
quantities have been in use in construction for over a century.
However, as paper documents they lack detail, flexibility and
authority. A 'smart' bill retains all of the detail of the building
at the most detailed component item level; it's flexible in that it
can be used for many purposes other than just tendering and
valuation and it's authoritative in that every item it contains can
be challenged explicitly, can thus be verified definitively.
The progress information used in production management is a
simple extract from the trade supervisor's daily diary. The man-hour
usage information can be obtained from the same source or from the
specialist contractor's time recording system. Obviously, the
Production Management system can be used to generate turnaround
documents for the capture of this information or to drive hand held
data capture devices or similar.