page contains answers to common questions, along with some
and tricks in customising and using PROBID,
(including the built-in
tools). You may find these useful.
We use a few shorthand conventions for describing user-interface
procedures. Key combinations are presented like this: [Ctrl][End], which means you
should press and hold down the Control key and the End key at the same time.
Menu selections are presented like this: Master,
New, which means that you should
go to the Master menu, and select New.
- How do I search for text in descriptions?
- Why doesn't my printer produce any output?
- Why does my printer produce garbage?
- What are Hyperkeys?
- What is "Gestalt Pattern Matching"?
- What is the JOTTER?
- What is a "User Defined List"?
- How do I change the program's Data Directory?
- How do I change the Report Header?
- Should I change the Printer port?
- Why do I get comma separators in numbers?
- Why can't I input dates like 23/10/02?
- How do I customise the program for different users?
- What is a "private" line?
- How do I create a NOTEPAD template?
- Arithmetic Expression Parser
- Why isn't my calc sheet saved?
- How do I use
- What is the point of templates?
- What is the "command line" version of PROCALC?
- Estimating & Tendering System
- How do I "unlink" linked Items?
- How do I clone just Operations?
- What happens when a Set is expanded?
- Can I use different Cost Types for different jobs?
- How should I handle Tender alternatives?
- Why should I round Tender Rates?
- What is "Quantity Loading"?
- What is "Front Loading"?
- How should I handle Provisional Items?
- What is a TOKEN Item?
- What are "Special Groups"?
- What are Auto Library Batchfiles?
- Contract Billing System
- My reports show some items out of order? Why?
- Do I need both Groups & Sections?
- What is a DEPARTMENT
- What are " Special Certificate Groups"?
- Project Scheduling System
- What is a Hammock?
- What is a "Control Activity"?
- Are PROPLAN and
PROBID Resources similar?
- How do PROPLAN and
PROBID work together?
- Is PERT COST a useful costing system?
How do I search for text in descriptions?
You can perform a complete
Gestalt search on both the codes and descriptions contained in any picklist. When
the picklist is on the screen, hit [F5], and type a fragment of
code - or text -
into the input field that appears below the list.
Press [Enter] to start
the search from the first record in the list, or [F5] to start at the next
record- the one following the current picklist highlight. The highlight jumps to
the "best matching" record. Text you enter in this field remains as a
default while the picklist is active - so [F5][F5] effectively repeats the search
for further records.
As with "loose" masks
- or Find and Replace - a
fragment that is all lowercase matches case insensitively while mixed or
uppercase search text matches case sensitively. [F4] will copy the highlighted
record into the input field so you can edit its text to create a starting search
Why doesn't my printer produce
If you are printing under a
Windows network, you may not have properly configured the printer so that
it is recognized. (See Printing from DOS Versions of PROBID, PROBILL, and PROPLAN running under Windows 95/98/ME/NT/2000/XP)
Why does my printer produce garbage?
You may have the
wrong Printer type selected in Customisation. Select Master,
Customisation, Printer Setup
and check to see that the Laser
Printer? setting is
appropriate. If you are using a Dot Matrix printer, make sure that the correct
model - or a suitable emulation is set. Also check that your printer's DIP switches are set to
produce that emulation.
What are Hyperkeys?
Most editing is performed
within the confines of a single screen. Normal movement
between these "screens" can take several keystrokes.
[Ctrl][PgUp] move directly between logically sequential screens (e.g., the
various Customisation screens).
For example, [Ctrl][PgDn], from the
screen in PROPLAN, displays the
Report Symbols screen.
again moves to the Country Setup screen. If pressed again it displays the
Colors screen- and so on. (Similarly,
[Ctrl][PgDn] from the
Activity entry screen
displays the Link Entry screen- as would
Once in the screens, [Ctrl][PgUp]
will move in the reverse direction.
[Ctrl][PgUp] is like a
"big" [Esc]ape key.
[Ctrl][PgDn] is like a "big"
What is "Gestalt Pattern Matching"?
A Gestalt or
"Intelligent Pattern Matching" facility resolves ambiguities created
by partial, ambiguous or erroneous entry. If user input does not exactly match
any one of a set of valid choices, the program intelligently evaluates the field
and finds the "best" match available - bearing in mind the relative
likelihood of different typographical errors and omissions.
This allows you to enter part
of a code, press [F5],
and have the program find the best record match for that code.
What is the JOTTER?
is a special form
of the NOTEPAD. The notes are not associated with any particular record but
with the whole job - if one is being worked on. Otherwise they associate with
the program installation itself.
is a convenient way to create
lists of "things to do", or record quick notes from a telephone
call. It is accessed with [Alt][J] or
What is a "User Defined List"?
You can create - and maintain - a personal
User Defined list of choices for many data
fields. If a field usually contains one of a limited set of options, this can
greatly speed data entry.
One example; if you frequently
create jobs for several different departments you will be repeatedly
changing the name in the Job details screen. You can add these details to a
file, by pressing [Shift][F6] from the name field.
When creating the next
job you can hit [F6] - the SELECT key - to popup a picklist of all the records in this
file. Select a particular department and the name will be copied into the field.
Another example; if you always use the same standard Measure
Units, it may speed up entry - and improve consistency in the use of
abbreviations - if you develop a user defined picklist. After entering a item, task or
resource measure unit, press [Shift][F6] to add it to - or amend it in - a picklist.
How do I change the program's Data Directory?
menu, Customisation, Directories,
just amend the directory
name and save the
change with [F2].
How do I change the Report Header?
menu, Customisation, Printer Setup, change the
standard Report Header and
save the change with [F2].
The program will automatically center
the heading as it is saved.
Should I change the Printer port?
PRN is the default output
device. This "logical"
MS-DOS device normally refers to a printer - regardless of how it is connected.
With the device set to PRN,
the program uses BIOS sensing for immediate feedback on
print errors. Screens and defaults then respond and adjust dynamically to the
If you want to switch between
two simultaneously connected printers - or have problems printing to PRN - you
can set this field to refer directly to a physical port. BIOS sensing is then
When printing over a Local Area
it is generally better to leave the device setting on PRN
and handle all port redirection at the LAN
Why do I get comma separators in numbers?
A Thousands Separator for
numeric values may be specified through Master
menu, Customisation, Country Setup.
This separator is used to
format the output of large numeric values. (Separators may also be entered in
most numeric fields. However, to simplify editing, their position is not
interactively validated and they are replaced by spaces before the field is
If a derived value is too wide
to display, the program first tries to fit it into the space available by suppressing
thousands separators. If the result is still too wide then the
number of displayed decimal places is reduced. If the number is still too big, an overflow indicator and an error
message is shown.
Why can't I input dates like 23/10/02?
Dates may be input in:-
format (e.g., 23Oct02),
numeric format s - DMY,
or relative format (+
days from the system date.)
Regardless of the entry mode -
or country settings - dates always appear in international ddMMMyy
format setting is controlled from Customisation,
How do I customise the program for different users?
Your choices from all the
Customisation screens are saved in a Customisation Template file in the system directory.
The program allows you to save and access
multiple customisation templates. These files all have a CTL extension and are
saved in the system directory.
Additional CTL files can be created by keying
from any of the customisation screens. A picklist of existing files appears -
an option to create a New File. An existing template can be re-activated with [Alt][R]estore.
It then remains current unless you switch to another job.
Jobs are associated
with their own template - the one active when it was created or last saved. When
you switch to another job, it automatically restores its own customisation
template. This means you can associate sets of jobs (different departments,
types of work, etc.) with different templates. The program then
automatically as you switch jobs.
When a customisation file other than the
default file DEFAULT.CTL is being used, the customisation screen headers show
the base name of the file.
What is a "private" line?
vertical bar character "|" used in the first position on
line produces a "private line" - effectively a comment that will not be
included in reports.
How do I create a NOTEPAD template?
In addition to associating NOTEPAD
details with particular records, you may save notes in separate template
[Alt][S]ave copies the current
to a file in the system directory.
[Alt][R]estore reads files back into the
The Save and Restore commands
provide a convenient way to transfer text between records - even in different
jobs - and between the NOTEPAD
and word processors.
[Alt][S]ave produces a
picklist of existing "templates" and allows you to add new ones.
[Alt][R]estore reads templates saved with
[Alt][S]ave or, in fact, any text file
with an ASC extension in the system directory. If just one
ASC file exists,
[Alt][R]estore reads it. If there are multiple
produces a picklist to allow you to select one. Hence, you can create a number
of templates - such as pro-forma Qualification letters, Work Orders, etc., and quickly select one to
import into the NOTEPAD
- Arithmetic Expression Parser
Why isn't my calc sheet saved?
Probably because you are not
exiting correctly or you have accessed the system version of PROCALC.
can be accessed in two
[Alt][=] calls a system version from anywhere
within the program.
On the other hand, if the cursor is in a numeric field,
(quantity, usage rate, production rate, unit rate, markup percentage, etc.), a
field specific version may be called with [Alt][C].
calculation is completed with [Alt][C], or
[F2], the formula is saved and
linked to the parent field. It can be re-accessed from that same field at any
time. You retain not only the calculated value but also the formula which
produced that value.
How do I use
allows you to use single character User Defined
Variables. For example:-
A=1.5 ;R is
now 3.25, A is 1.5
C = A + R : A=a + 5 ;C is 4.75, A is now 6.5
4 * C/10 + A
;line value is 8.40
r=10 : h=20 :R x H/2 ;line value is
A variable value set on one
line can be used on subsequent lines.
What is the point of templates?
They facilitate reuse of
standard calculations, tables of values etc., - saving time and avoiding
You can save a calculation
sheet with [Alt][S]ave and the saved lines can be brought back
[Alt][R]estore work in much the
same way in PROCALC, the
The file extension for PROCALC
template files is PCL.
(The extension for the
files is ASC.)
will also read externally prepared text files with these
extensions back into either PROCALC
or the NOTEPAD-JOTTER.) Hence, you can
create and reuse multiple calculation templates that are independent of a
particular job. These could be complete conversion charts for weights of
steel sections or reinforcing bar, or standard trench cross section areas, or a
"spreadsheet" for calculating an "all in" labour rate from
basic award provisions.
What is the "command line" version of
The command line version of PROCALC
is a stand alone program that can be run from the MS-DOS
Most facilities and functions
in the command line version of the PROCALC
freeform arithmetic expression evaluator, parallel those in the integrated
version. However, there are some necessary differences.
This version can be passed a
command line expression to evaluate, e.g.,
43.5 + 2 * 23.5/(7.8 + 2.1)
If no command line is provided
it operates interactively and continues evaluating expressions typed in until
there is no further input. It then shows a grand total for all the entries.
Input and output can be
redirected in the normal way. Hence:-
PROCALC (234.7+176.2)/44 > PRN will print the results, and
PROCALC < TAKEOFF.LST
will read the file TAKEOFF.LST and evaluate each line
in the file as an arithmetic expression.
Much like an adding machine. PROCALC
has the equivalent of a "paper tape" as all input and output is
written to a text file PROCALC.LOG.
If you are running PROCALC
from a Windows DOS box, the input and output is copied to the Windows clipboard
so that the calculation details can be pasted into other programs.
- or PROCALC /H
- from the command line will produce a brief description of the program's syntax
and list the built-in functions. (In interactive mode, typing ?
displays all user defined variables.
will display a PC-8
- Estimating & Tendering System
How do I "unlink" linked Items?
Linking is most commonly
done when estimate items are cloned from the Utility
menu. If you clone -
and link - a number of items you may subsequently find that some of these items
should not have been linked as they do not really cover the same type of work as
their parent item. (An item may be linked to
another so they share the same operations. Pricing one item effectively prices
the whole family of items!)
You can Link - and "unlink" -
individual items with [Alt][L] from the Item entry screen. Fields appear at the bottom of the screen
for the group, section, and item code of the target item to which you wish to
link. (The item shown as a default link target is
"guess" based on code similarity.)
Amend the code - or use [F6] (or
[F7]-[F8]) - to find the correct item.
How do I clone just Operations?
From Change Operations mode,
with the cursor in the description
field, [Alt][D]elete and
[Alt][I]nsert act on
operations as if they were a visible list of similar fields. Deletions are saved
in a "Cut" buffer and insertions "Paste" from that buffer.
Hence [Alt][D]elete, followed by a number of
"clones" the current operation.
The technique may also be used to copy
an operation from one item to another.
What happens when a Set is expanded?
Using sets - rather than having
to redefine the same crews and "assemblies" every time they are
required to price an operation - saves time and avoids mistakes of omission.
This capability should be used
to "automate" the production of tenders as much as possible. If you
have a number of sets differing from each other only slightly (e.g., pipe laying
crews varying only by the
size of the excavator) they can be created very
quickly by cloning records and editing.
However, there are times when a
set needs to be used - but its makeup changed slightly - just for one particular
operation or item.
If a set is entered in a code
field in the operation pricing screen, you can "expand" or
"explode" that set into its constituent resources, sets, and
subcontractors, with [Alt][E]xpand.
The set code is replaced by the first
element of the set, and so on progressively down the screen.
If a set quantity has been
specified, the element quantities etc., are computed using the set quantity and
the element usage rates. The element pricing mode generally mirrors the original
Expanding the set is then equivalent to directly entering each element in
the proportion in which it is contained in the set.
Can I use different Cost Types for different jobs?
Customisation templates cover
all customisation screens so [Alt][R]estoring a
template file resets all
customisation choices - including Cost
You can save any
number of template files and switch between them. Different users can have their
own file to personally configure
PROBID, or a single user could have files for
different regions, types of work (Civil, Mechanical, Building, etc.), printers,
When it is first run,
creates a default customisation template file - DEFAULT.CTL - in the system
To create additional template
files, hit [Alt][S]ave from any of the Customisation screens. Enter a filename when
prompted. Customisation template files are automatically given a CTL extension.
[Alt][R]estore - from any Customisation screen - pops up a picklist of these
files so you can switch configurations.
Each job "remembers"
the Customisation file with which it was last associated. When the job is opened
again it automatically re-reads that template file and reconfigures
will then respond
automatically, as you switch from estimate to estimate, to ensure that the Customisation
defaults are correctly reset for each different category of job.
How should I handle Tender alternatives?
Estimate libraries offer the
most flexible way of handling alternatives in either the estimate or the tender.
Placing the alternative
resources - and/or items - in job specific libraries, means you can
maintain one estimate and still bring those records back into the job when you
want to present - or consider - a particular alternative.
The other approach - creating
several different estimates by copying - should be avoided. It may become difficult to
maintain the common portions of each estimate, if the alternatives represent
only a small proportion of the total tender.
Why should I round tender rates?
A common criticism of a
computer prepared tender is:-
"it looks as if it has been prepared by a
This remark is usually provoked by ineffective (or even
non-existent) numeric rate rounding procedures which produce too many unnecessary and
non-significant digits in submitted rates and
The criticism reflects
more than just a concern with presentation. To ease contract administration, and to
disguise the estimate
makeup, unit rates should be properly
"Raw" tender rates
can convey too much information on the Contractor's estimate makeup - and markup
- to competitors,
has sophisticated options for intelligently rounding rates,
amounts, and tender totals. It mimics the manner in which a conscientious
estimator manually rounds submitted rates - without risk of error and without
the tedium of chasing "balances" to produce the required tender total.
is "Quantity Loading"?
If a tender item's contract quantity
is known to be significantly wrong, a tenderer should - at
least - take "defensive" action to protect
his recovery of overhead and other indirect costs.
If the contract is remeasurable (i.e. a
"Schedule of Rates" or
"Unit Price" contract)
you to easily protect yourself - and even take advantage of the error.
contract and actual quantities ensures that your estimate is
"correct" - you are fully protected from loss of indirects and overheads.
appropriately "fixing" and "loading" the submitted item rate
you can actually take advantage of the error.
"Under billed" items can
have their rates pegged higher than the normal direct cost, plus a proportional
share of indirect costs and markup.
"Over billed" items can -
conversely - be set lower.
To do so, define the item as a FIXED
manually fix a unit rate or percentage spread.
If the contract is "Lump
Sum" (i.e., there is no payment adjustment for changes in quantities) you
cannot overcome the problem by entering different contract and actual
quantities. The contract quantity itself must be corrected or, if this is not
possible, it must be converted to the correct quantity at the operation level.
PROBID's tender analysis sheet clarifies these complications with a tabulation
showing the difference between nominal (contract quantity based) and actual
Of course, you must be aware of the risks and contractual limitations on
unit rate loading. Owners frown on the practice and may not accept obviously
"unbalanced" tenders. Design, or "scope of work", changes
can alter the actual quantities - perhaps even reversing the original imbalance.
When the actual quantity differs from the contract quantity by more than a
specified percentage, some contracts allow for "appropriate"
adjustment of the unit rates (although the adjustment is usually based on the
original unit rate and so does not fully remove the advantage gained by
See also Front
is "Front Loading"?
Long term projects have
significant cash flow implications for the Contractor. One way of improving cash flow, without
affecting overall contract value, is to "move" revenue from items
executed late in the project to those executed - and paid for - early.
facility for setting items as FIXED
makes selectively "loading" a tender extremely easy.
"front" loading can conflict with the need to "quantity"
load items - in which case the latter normally takes precedence.
loading is subject to the same hazards for the Contractor as quantity or rate
should I handle Provisional Items?
When a tender contains
"write in" or
"provisional" items with arbitrary quantities -
or items that may be deleted from the contract before it is completed - you should define them as
This protects you in two ways.
No markup or other spread is assigned to the items and, when percentage markups
are calculated, their value is not considered part of the cost base.
Alternatively, if you are confident that the quantity is over or under assessed,
you may consider an appropriate "quantity loading".
What is a TOKEN Item?
TOKEN items appear in the
tender with submitted rates and amounts equal to their direct costs. They are
also excluded from the cost base when calculating percentage markups.
"artificial" tender items - i.e., items that do not represent real work;
or are not likely to proceed in their present form; or are not of financial
interest to the tenderer. Typical examples:-
|"Write In" allowances
defined in the documents.|
| "Nominated Subcontract" amounts specified
in the documents.|
| Provisional items unlikely to be used.|
| Work performed by
other divisions of the company (when the quoted "cost" already
includes markup, so it is unnecessary to mark it up again).|
What are "Special
allows you to use a
special script file to specify that the cost totals - and
contribution - from particular groups, is to be
summarized in a table at the end
of the item and operation unitcost reports.
This is a convenient way to show
the percentage cost contribution from Site
Overheads, Head Office
This text file,
UNITCOST.GPS, is just a list of the group codes - or code masks covering a set of
groups - to be shown in the tabulation. No special header lines are required. The
first two characters on each line are interpreted as a group code or mask.
file must be in the system directory.
A Total Cost will be shown for any group
defined in both the script file and the estimate.
What are Auto Library
You can automate the process of
copying selected library records into new estimates with special
"batch" files. These must be plain ASCII text files with an extension
They can be prepared with a word processor,
text editor, or the
ALB files when a new estimate is created. If no
ALB files exist, it proceeds as
normal - so the casual user need not be familiar with, or even aware of, the
facility. If just one ALB file is found, it is automatically read and the
specified libraries accessed. If more than one is found, a picklist appears for
you to choose the appropriate file.
Each active line in the file specifies a
source library file and a full selection mask. Comments may be created with
semicolons - or by enclosing text in braces or square brackets, as in PROCALC.
- Contract Billing System
My reports show some items out of order? Why?
When group, section, and item
codes are being assigned, their sorting order must be considered. Characters are
position and case significant and
ASCII value fixes their ranking.
For the common
characters, this order is:-
|Upper case letters (A-Z)|
|Lower case letters (a-z)|
Pre-planning of group, section, and item codes is
vital to ensure that items sort in an appropriate way. Nevertheless, if the coding of the
groups, sections, or items-or suppliers, sets, or resources - turns out to be
unsuitable, you may be able to change it "en-masse" through the
Utility menu, Find and replace option.
Of course, you can choose not to sort
reports - but then group and section subtotals will not be given.
Do I need both Groups & Sections?
If a contract contains only a
few items, the group and/or section division may be skipped - just leave the
codes and descriptions blank.
At the other extreme, a large number of items
may be organized into a two level hierarchy - perhaps "Bills" and
trade sections within the Bills, or "areas" and work classifications
by area, etc.
PROBID's group and section structure can parallel the
organisation of any single or double level item subtotaling scheme.
has an alphanumeric code and a description. In turn, sections may be
classified into groups.
Item codes must be unique within a section and section
codes unique within a group.
What is a DEPARTMENT SUMMARY?
The DEPARTMENT SUMMARY is a
multi-job report. It includes all jobs in the PROBILL data directory, with the same
department code as the current job.
Each job is summarized on one line and
department totals are shown. This may be useful on a large project broken down
into many subcontracts - or to provide an overview of all jobs administered by one
department of a larger organisation.
If all department codes are blank, all jobs
belong to the same "department" and are included in the report.
Back to Top
What are Special Certificate Groups?
PROBILL allows you to use a
script file to specify that certain groups are to be shown in a tabular
summary in the body of the Progress Payment
It might, for
example, be used to specifically list the totals payable for Variations,
Materials on Site.
This text file is
just a list of the group codes - or code masks covering a set of groups -
shown in the tabulation. No special header lines are required. The first two
characters on each line are interpreted as a group code or mask. The file must
be in the system directory. An amount todate will be shown for any group
defined in both the script file and the contract.
- Project Scheduling System
What is a Hammock?
represent a portion of a network. They are defined in a similar way to activities, except that:-
|No Calendar is specified - it is
always the System calendar.|
|No Duration is specified - it is calculated during
|No predecessors are entered - the hammock "hangs" from
its Start and Finish activities.|
You must give the hammock a
code and a
description and may, if you wish, also assign
The scope of the hammock is given by specifying a
The hammock's duration, dates and floats are all calculated from the dates of
its Start and Finish activities. (The duration and float will be in calendar
days - not working days - even if the spanned activities happen to have a common
Hammock definition is completely
flexible - the
"constituent" activities need only form a loose grouping -
you should ensure that your choice of start and finish activities makes sense.
What is a "Control Activity"?
Many "real world" projects -
"linear" construction like highway,
pipeline work -
of several loosely related mini-projects that could proceed in parallel if
unlimited resources were available, (e.g. earthworks between mass haul points
Much of the constraint in the schedule is, in reality, the
economic one of providing reasonable levels of equipment, labour or
supervision, at any one time.
This problem can be addressed with the
techniques of resource constrained scheduling, or resource leveling. However
there are serious practical difficulties in implementing either of these
approaches and computer models will always produce results which are
sub-optimal and do not reflect the complexities of real projects.
realistic analysis is often possible if "control" activities are
A "control" activity is defined covering the total amount of
each work type (e.g. asphalt
paving) embodied in the separate activities from
The duration of the control activity is the
total duration for that type of work given reasonable and "economic"
resource levels. The individual activities are linked to the control with
Finish links of zero lag.
The effect within the network is to make the control
activity critical while the individual activities "float" within the
span of the control. (It may not be important to be paving in any
one area of
the job, as long as paving is underway at maximum output in some
sequence of control activities can themselves be linked with appropriate
logical links and lags.
This produces a much more realistic network model that
recognizes the multiple resource constraints without suppressing the inherent
real flexibility that exists in the way individual activities and areas of the
project can be worked.
The Project Manager is able to exercise his judgment in
assigning priorities within this overall framework. That judgment will reflect
his explicit - or intuitive - assessment of complex issues such as resource
substitution, the "costs" of idle or poorly utilized resources,
uncertainty in duration and productivity estimates, the relative importance of
certain tasks - as well as the risk associated with delaying those tasks - in a
way that still defies computer modeling.
PROBID Resources similar?
While superficially similar
(they both have codes, descriptions, costs, etc.) the resources used in PROPLAN
also differ in several respects.
Reusable (e.g. carpenters, bulldozers, power demand, systems analysts,
office occupancy, batching capacity) or Consumable (e.g. bricks, concrete,
cash, energy consumption, computer time.)
resources also have an allocation
mode. This may
Daily usage, Fixed
amount, or Start or End
The allocation mode allows you
to distinguish between resources whose consumption is dependent upon duration
and those whose consumption is fixed.
The latter can be allocated as total
amounts in three different ways - as a "Fixed"
allocation, which the
program will evenly spread over the activity duration, or totally on the Start
or End day.
The default is by a Daily usage
rate. This may be appropriate for
labour, equipment and supervision if the work force is constant - and hence the
total usage varies with task duration. This is common where a fixed crew is
assigned to a task and the duration depends upon its productivity.
total consumption of a resource depends upon the physical amount of work to be
done, and is not directly related to the time taken, the allocation mode
should be by "Fixed" amounts.
This is typically the case with
materials such as bricks and structural steel. It may also be true with labour
or plant if the productivity rates are reliable and the time taken depends
only on the number of men or pieces of equipment assigned to the job (often
the case with jobs like bricklaying, steel erection, welding, or ripping.)
Fixed resources PROPLAN
spreads the total amount allocated to a task
over its duration. Special allocation modes can be specified if the demand for a
resource occurs all on the first or last day of a task.
day" allocation mode may be required for consumable resources that must
be available in total on the day work starts - perhaps for reasons of economy in
transport or unloading.
An "End day" allocation mode is often
appropriate for materials like concrete. An activity covering the forming,
fixing of reinforcement and placing of 500 m3 of concrete could take five days
but the concrete may all be poured on the last day. If we were attempting to
assess the peak need for transit mixers or concrete finishers it would be
completely wrong to spread the concrete demand over the five days as an
average of 100 m3 per day!
resources - as scheduling elements - also tend to be defined at a higher level
- which have to capture all the detailed costs that go into an estimate. In
resources may more closely match
See the next
topic for more info.
How do PROPLAN
PROBID work together?
If you are using
- PROCON's Estimating & Tendering System - to produce your project
estimates and tenders, you can export activities, operations, resources, sets
and costs directly from the estimate to create a basic network plan.
can then refine this network and produce Bar
Charts, Resource Loading
histograms, Cash Flow
histograms, etc., that support the tender submission and
help in the estimate analysis of resource requirements and overheads.
project information like the job name, password, department, job number, start
date, duration and finish date is copied from the estimate to create an
network. The project start and finish dates become the
network data date and specified end dates respectively.
Some of the
items, operations, resources, sets and costs are also copied to the network.
activity is created
for each operation assigned an Activity Code. The activity description,
calendar, duration, start and finish date, costcode, measure unit and budget
quantity are taken directly from the
dates as "PUSH" (Earliest Start) dates, and Finish dates are
"PLUG" (Latest Finish) dates. Any difference between the dates and
the duration is float.
resource or set, used by an activity, is
copied into the PROPLAN
network as a resource. (Sets are treated as if they
were a resource.)
Allocations of defined resources and sets are treated as
assignments of consumable PROPLAN
resources. These allocations are treated as
fixed amounts equal to the calculated element quantity.
Any other operation
costs (i.e., from subcontractors or undefined resources or sets), are assigned
to the activity's direct budgeted fixed cost or budgeted unit cost - as
can then be used immediately to produce a simple Barchart
or Resource Loading histogram or the network can be further developed by
defining specific work calendars, logic links, milestone dates and hammocks.
also exports all estimate cost and revenue data in a form designed to
assist the estimator in producing a quick cash flow analysis of both costs and
It is often not practical - and should not be necessary - to define every
operation as a PROPLAN
activity and assign it a code, calendar, start
date, etc. (An estimate often contains many operations that have to be priced,
but would not be included in a project schedule.)
However, for costing and
revenue and cost cash flow projections it is essential that all costs, etc.,
are transferred to the PROPLAN
item is copied to a
hammock. The hammock code, description, measure unit,
budget quantity and bill unit rate are taken directly from the item. (If a
items have the same code, the hammock codes are made unique
by appending sequential lowercase alphabetic characters.)
The hammock's start
and finish activity codes are taken from the activity codes in the item's
operations. The start activity is taken from the operation with the earliest
start date, and the finish activity from the operation with the latest finish.
This ensures that the hammock spans all of the item's operations.
item's have no operations - or no operations with activity codes - the export
facility will create two dummy "activities" to represent the job
start and finish and uses these as pivots for the "unhung" hammocks.
hammock's budget quantity is set to the
quantity, and the bill unit rate to the item's submitted rate.
REVENUE CASH FLOW report can then produce an immediate projection of periodic
billing amounts and the profile and interest cost/value of the projected
This export facility also creates a set of artificial PROPLAN
"resources" and allocates these to the PROPLAN
resources are dummies for various cost and revenue combinations, so that the
hammocks can capture the detailed cost breakdown from the corresponding
can then produce
RESOURCE LOADING histograms for any of these
dummy "resources". These resources are Consumable, are allocated as
Fixed Amounts and are measured in thousands of currency units.
cost type (Labour,
Subcontract, etc.) will typically have a
different disbursement lag. This detailed breakdown by cost type provides the
estimator with the option of fine tuning cash flow projections to
produce more realistic figures for interest cost. The job cost and revenue
detail is thus provided in several different forms. Before working with job
totals of budgets or cash flow you must decide which form best suits your
needs and disable the presentations that are not required. The hammock
resource allocations can be removed by deleting all hammocks, deleting the
artificial resources, or just zeroing their unit cost.
Is PERT COST a useful costing system?
Having broken a project down
into tasks for purposes of time control, it seems only logical that we should
use that same breakdown for cost control.
The resource assessment, required to
estimate durations, could be used to generate a budget for each task - and hence
a budget or "estimate of cost" for the complete project.
assessment for time reporting could be tied in with valuation assessment for
cost reporting - avoiding duplication of effort and providing some assurance
that the two processes are harmonized.
This approach to costing - called PERT
COST because of its early association with PERT networks on major defence
development projects - is the basis for all the costing systems "built
in" to Project Scheduling software, including PROPLAN.
intuitive appeal, attempts to apply PERT COST concepts in the construction
industry have been particularly unsuccessful. Some of the reasons for this
|A task breakdown is determined by precedence
logic - a cost breakdown
should be determined by the logic of work similarity. When this is done, cost centers
usually cut right across the task breakdown.|
|The granularity of the
breakdown rarely matches. Tasks often include work of many different types -
cost centers usually include work from many areas and stages in the
project. Things that are important for purposes of time control (approvals,
etc.) are not as important for cost control and vice versa.|
frequency, completeness, and required accuracy, differ. Valuation and cost
reporting is usually undertaken at the end of fixed periods (daily, weekly, or
monthly) while time progress reporting should be an ongoing process with the
timing of formal updates determined by project status.|
|The resource and cost
assessment required for a budget - or cost estimate - is vastly more detailed than
that required to develop a time plan. When task duration is determined by
resource availability/usage (and often the reverse is the case) it is usually
dependent upon only one or two "key" resources. In this case it is
only necessary to consider these resources in time planning. Estimating and
Costing must deal with all resources and costs.|
capabilities that address some of these problems:-
|A single costcode can
cover any number of tasks - so costs can be allocated to broad aggregates, while
valuation is still performed at task level.|
|Hammocks - as well as
activities - can be directly costed. This provides more flexibility in handling
overheads, indirects, and "global" costs, by avoiding the need to
artificially spread common costs over sets of activities.|
|Resource based or
directly allocated costing - or both - can be used.|
|Directly set budgets can
combine a fixed and quantity related component.|
|Valuation progress is not
rigidly tied to time progress.|
Nevertheless, PERT COST cannot be recommended
as a viable substitute for properly designed construction job costing