The management of welding procedures is one of
the most time-consuming jobs of a welding engineer. Creating, verifying and
approving new procedures and checking, adapting and approving existing ones
take a ling time. Plus, searching for existing procedures for new production
welds requires expert skills. Consequently, this was one of the first
welding engineering tasks to be computerized.
The first welding procedure database management
systems were simply electronic filing cabinets. They used the speed of data
sorting that computers could offer to make searching for existing procedures
much quicker. Documents could be copied and edited to create new documents
quickly and easily. What they could not easily do, however, was help the
welding engineer create new procedures for new application.
The sources of such information are wide and
disparate. They comprise standards (welding and application), consumable and
base material handbooks, technical literature and – most
difficult of all to computerize – experience. To build all
this into a computer program would be impossible without a wide knowledge of
the sources available.
Taking all this into account, The Welding
Institute (TWI), Cambridge, U.K., and C-spec, Pleasant Hill, California,
have collaborated to develop a new version of Weldspec. Weldspec 4 has been
designed to help the welding engineer write and draft new welding procedures
while still giving the benefits of speed and editing of existing procedures
in Microsoft Windows®. The software comes from many backgrounds, including
the following:
- Worldwide welding and application standards
from such organizations as ASME, AWS, European standards and API
- Industry practice in developing, qualifying
and using welding procedures
- Typical interactions between customer,
fabricator and inspector
- Welding engineering and metallurgy
- Software development and knowledge
representation techniques.
Software so vitally based on knowledge and
recommendations from standards needs to be frequently updated; indeed, ASME
IX is updated annually. Because anything hard coded within software is
difficult to change, Weldspec's knowledge base is stored externally to the
main program so it can be modified.
Managing welder performance qualifications (WPQs)
is very similar to welding procedures: Both are designed by standards.
Variables that must be recorded, the extent of approval given by a test and
the destructive and nondestructive examination (NDE) regimes are specified
in national and international standards.
However, unlike welding procedures, WPQs are only
valid for a specified time without practice or additional testing.
Certificates expire, so the fast sorting capability of computers is even
more beneficial. By integrating another program called Welderqual 4 with
Weldspec 4 to share a database of welder details, WPQs can be created
directly from welding procedures.
Production Welding and Quality
Control
The management of welding procedures and
performance qualifications can save time and reduce errors. However, if this
is integrated with software to manage production welding and quality
control, the benefits can be multiplied. Most fabricators work in a compartmentalized way. The functions of
design, engineering, production and quality control are discrete, and
communication is often difficult, which creates problems.
First, errors in the design stage of a
fabrication – often due to bad communication – are
expensive to rectify once a weld has been completed. Simultaneous
engineering, where all personnel can contribute at all stages of
manufacture, is particularly relevant to fabrication.
Also, it is difficult to monitor fabrication
because paperwork can take a long time to circulate. This means problems can
become serious before they are identified.
Plus, the sheer weight of paperwork can make it
very difficult to update welder performance qualifications based on
satisfactory production welds. Many fabricators retest welders
unnecessarily. Also, it can be very difficult to identify those welders
whose qualifications are close to expiring.
Similarly, it can be very difficult and extremely
time consuming to collate project data books, simply because of the amount
of paper.
The Solution
An integrated software system such as Welding Co-ordinatorcan help.
Welding Co-ordinator is designed to be used live to manage fabrication as it
is progressing. It is usually based around an electronic weld map, weld data
sheet or weld schedule, into which data are entered as welds are designed,
engineered, welded and tested. The weld map would also usually have some
space for approval, either weld by weld, or once a project or structure has
been completed. Figure 1 shows a detail of a typical weld map for a
fabricator in the power generation industry.
Data are usually entered into the system from
four functions, as follows:
- At the design stage, where information such as
the weld ID number and other design parameters (material type, thickness,
joint type, etc.) are entered.
- At welding engineering, where a procedure is
assigned. It may also be possible to identify suitable welders or classes
of welders qualified to make the weld, although this is more likely to be
done at the production stage.
- At production, where the completion of a weld
is registered (usually by entering the date) and visual inspection carried
out and approved.
- At quality control, where acceptance of the
weld is registered. This may be simply by typing test report numbers into
the system, or it may be done with live links to electronic NDE
reports.
Note that data should be entered live into the
system as fabrication progresses.
The system also gives instant progress reporting.
Anyone with access to the system can see how fabrication is progressing.
This may be simply by looking at the weld data sheet on screen or by
explicitly programmed progress reports. These can identify bottlenecks (by,
for example, comparing the number of welds competed with the number of weld
radiographed), or help to produce reports for stage payments in large
projects.
It also provides automatic assignment of welding
procedures and welder. If enough information is supplied at the design
stage, the system searches through a database of procedures for suitable
welding procedure specifications (WPSs). This may be a single WPS of a
number from which to choose from, with a click of a mouse button. Having
chosen a suitable WPS, the system searches through WPQs for qualified
welders. If necessary, the system can list welders in order of their
certificate expiration dates – with those due to expire soonest at
the top of the list – so maximum benefit can be made of extending
their qualification.
The software also produces test requisitions
automatically. The system automatically produces NDE requisitions based on
the NDE requirements for the project. These can be selected manually, or the
system could randomly select welds for testing.
The system can also produce reports on repair
rates per welder (to identify training requirements), by procedure (to
highlight defect-prone procedures) or by any other measure, providing the
relevant data are recorded.
It also automatically generates document packs on
completion of a project. A very time-consuming task manually, it's again
ideally suited for computerization. With the click of a button, the system
can print the weld maps for a project, along with all the WPSs used (with
backup procedure qualification records [PQRs] if necessary and all the WPQs,
which are updated automatically based on satisfactory production welds. In
addition, if NDE specifications have been used to report testing, the system
can print relevant NDE reports as well. This information can also be
archived on CD.
It can also instantly trace production welds to
the information backing them up. If the inspector wants to see a WPS that
was used on a weld, or proof that the welder was suitably qualified, this
can be done with the click of a button. This can be especially useful while
inspection a structure after a number of years of service. If a defect is
found, the engineer can access the original WPS, for repair purposes, or the
NDE report, to see if evidence of the defect was present at
testing.
Problems and Pitfalls
Of course, these benefits come with some
paybacks and pitfalls. First of all, for any customized software, it is
critical to identify and approve requirements early on for all personnel who
will use the system. In practice, the software developer and the fabricator
will collaborate in producing a list of requirements, and both parties will
sing the document. This is a baseline from which the system is designed and
developed, and is used to measure the quality of the software produced. It
works for both the fabricator and the system developer. Also note producing
a requirements document takes time, which must be taken into account when
integrating any such software package.
Second, a system such as Welding Co-ordinator affects
many people, as it is, by its nature, a multi-user program. Any form of
change is often resisted, so it is important to identify all potential users
of the system and involve them in the requirements analysis stage. Any users
not involved in this stage can claim the system does not do what they want.
This may be because it makes their job harder, or it can be used as an
excuse to avoid change.
Finally, it is very tempting to develop the
system to be too prescriptive. For example, it is possible to develop the Welding Co-ordinator system to
allow only the selection of welders who are registered in Welderqual as
being qualified. In practice, however, the qualification test may have been
taken, but the NDE results may not have been received. Prohibiting selection
of that welder would not be correct in such circumstances.
Arguments often arise between QA/QC personnel and
engineering staff on how prescriptive to make the system. Experience shows
it is preferable to err on the nonprescriptive side, at least in the early
stages of system implementation. After all, it is always possible to modify
the system later, if it has been designed
properly.
