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PDMS
PDMS is a specification-driven, 3-dimensional (3D) modeling system,
consisting of a single relational database management program
and several separate and distinct modules, each performing a unique
function. Unlike many CADD systems, many of which began with a
graphics package and later added database capabilities, PDMS'
designers approached plant design as a true data management problem.
Their solution was to establish a database core and provide methods
to display the contents graphically. This approach eliminated
the problem of synchronizing the graphic and data components of
a graphics-based CADD system.
PDMS' database architecture imposes no unnecessary limitations
on a project. It doesn't require that a project be broken into
separate "sub-models" for simultaneous data input (which
must subsequently be merged in order to view the entire structure).
Instead, several designers can be working on the model at one
time, and each can view the entire project or a selected portion
of it as he builds the elements in his part of the model. With
PDMS, project management can monitor the progress of a project
at any point in the design cycle without disrupting the work.
From information provided by supplier drawings, engineering sketches,
piping layouts, and mechanical flow diagrams (MFDs), designers
build equipment, structures, and piping into the PDMS database
at full size. As work progresses, operators routinely monitor
data consistency via the Datacon module or via the interactive
design module. This function ensures that all components are connected
and that all connection types are compatible. It also ensures
that lines have consistent bore and alignment. In addition to
data consistency, the system is used to check for interference.
The Clasher facility checks any designated section against the
model to detect "hard" clashes (such as pipe hitting
cable trays) and "soft" clashes (such as brace members
protruding into walkways). Maintenance areas used for rodding
or pulling tubes are designated as restricted areas, and any intruding
objects can be identified. The system can also detect lines that
are too close for insulation application and hand wheels with
insufficient clearance for operation.
Like its plastic counterpart, the computer model is a true representation
of the project. Each component is a distinct element in the PDMS
database. Unlike its plastic counterpart, however, the computer
model can be modified to accommodate design changes and to correct
errors without having to start over each time such an error is
found. Additionally, the computer model provides the drawings
and the documentation required to fabricate and construct the
facility.
At any point in the project, "snapshots" can be taken
of the model. These snapshots can take the form of a perspective
view of the structure, a report listing the completed lines, a
preliminary material takeoff, an input file to the dynamic model
review program, or any other graphic or data report that may be
required. Once the model or a designated section of the model
is complete, the program can produce the following:
- Piping isometric drawings, with material lists and cut lengths
- Material takeoff reports formatted for input into JRME's estimating,
ordering, and tracking system
- Conventional piping plans and section drawings
- Descriptive drawings to clarify congested or unique areas
- Overall perspective views for fabrication/construction planning
- Input files for the model review program (Review)
- Reports formatted for input to center-of-gravity programs
- Drawing files for use in AutoCAD
- Weld count reports
- Input files to the pipe-stress analysis program
- Structural plans and elevation drawings
- Exploded sub-assembly drawings to aid fabrication/construction.
Completion of the project's design phase doesn't signal the end
of the model's usefulness, because the database can be transferred
to CADCentre's Review software to allow real-time, color-shaded,
walk-through plant review. Review was designed to be operated
by people with no PDMS experience. It is mouse-driven and has
pop-up menus that allow the user to "walk" down plant
corridors well before the facility is constructed. It can be effectively
used for orientation and operator training (since it allows users
to get inside the plant) and can be projected onto a screen for
several people to see at once. An added benefit is that lines,
equipment, nozzles, and even support steel can be located by name,
and member names can be obtained by clicking on the element.
There are many advantages to assembling a 3D numerical model.
All the justifications for building a plastic model apply for
the 3D model, with the added benefit that the 3D model costs much
less and its cost is included in the design phase. Additionally,
the 3D model helps ensure an error-free design by producing accurate
drawings and reports. However, the two most important benefits
are significantly reduced fabrication and erection errors and
faster startup time.
AutoCAD
AutoCAD is the most widely accepted drafting program in production.
Easy to operate and independent of centralized computer systems,
AutoCAD provides speed and flexibility that mainframe-based drafting
systems cannot achieve.
Our electrical, instrumentation, and structural drafting groups
are AutoCAD's chief users. PDMS drawings are converted to AutoCAD
format and used as backgrounds for electrical lighting plans and
for other purposes. Additionally, AutoCAD can access the large
drafting libraries JRME has accumulated over the years.
We can also use piping flow diagrams provided to us in AutoCAD
format: this reduces the time necessary to complete MFDs and to
begin inputting the PDMS model, which can improve the overall
project schedule.
AutoCAD has a drawing exchange format which provides us with
an important link to suppliers and customers who also use AutoCAD.
Because this exchange format has been widely accepted, drawing
transfer to other systems is also possible.
Intergraph PDS
JRME has the capability to use PDS in both the 2D and 3D modes.
PDS has powerful integration features that allow engineers and
designers from all disciplines to work on a project simultaneously
and share up-to-date information. This capability eliminates duplication
of work, improves coordination, reduces errors, and increases
productivity.
PDS includes an advanced suite of schematic modules for front-end
engineering design of process and utility plants. These products
are integrated with the PDS 3D modules for optimal information
control. PDS schematics include PFDs, P&IDs, and instrumentation
data management (IDM).
These modules correspond to the basic tasks in the plant design
workflow. The database supporting the schematic design process
(PFDs and P&IDs) is the same database that supports the equipment,
piping, and instrumentation engineering tasks. This facility eliminates
redundant data entry, improving engineering productivity and quality.
PDS PFD schematically defines an entire process system and incorporates
this information into the database for use in other PDS modules.
PDS P&ID provides versatile tools for efficiently creating
the schematic definition of a plant and facilitates production
of drawings, reports, and materials estimates.
Conversion Software
An engineering firm must be able to deliver drawing files for
use with other drafting systems. JRME can convert PDMS drawings
to the generic DXF format for transmission to other systems. Third-party
software firms are available to develop direct translators for
transferring drawings between systems.
We know of no translators available to convert a 3D model from
any one system to another. PDMS offers such a rich database that
we feel the benefits provided would be lost in such a translation.
PDMS also runs on several types of computers (WINNT, IBM, HP,
Silicon Graphics), so we encourage anyone wanting to take advantage
of post-design benefits to obtain a copy of the PDMS program.
This allows us to transmit the entire model for maintenance, training,
and improvements, among other benefits.
In-House Software
The need for customized applications always exists, regardless
of a drafting or modeling system's sophistication. At JRME, we
continually enhance and extend the uses of our CADD systems to
improve their productivity and ease of use. These improvements
range from element-creation macros to engineering-initialization
software to data-extraction routines. In addition to our user-level
application enhancements, we develop systems to aid engineering
and to enhance the conversion of engineering information into
drawings.
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