Using 'expert' software packages, computers can make life easier for the welding engineer
A D Brightmore and M Bernasek
Paper presented at the 8 th International Conference for Computerization of Welding Information sponsored by AWS, Detroit, Michigan - September 1999 and published in the January 2000 issue of the AWS Welding Journal. (Vol.79, No.1, pp 43-45).
A D Brightmore is Manager, Software Development, TWI, Cambridge, UK. M Bernasek is CEO of C-spec, Pleasant Hill, Calif.
Welding engineers have managed welding procedures and welder performance qualifications using computers for some years now. Engineers now readily access vital information - no more searching through piles of paper. They can easily develop procedures and qualifications through on-screen editing, get advance warning of expirations and produce a professional-looking document in the end.
Most fabricators now have local or wide area networks so sharing information between key personnel is easier than ever before. Computers can integrate management of procedures and qualifications with production weld information and quality control (QC) data, and so the benefits abound.
Computers have always been good at storing, sorting and searching through large amounts of data, making them suitable for pure database applications. Such applications have required the user to know certain parameters, with little or no help from the software. In welding, such systems have been used for managing welding procedures and welder performance qualification. But, to date, most have had limited, if any, expertise in welding.
The problem with building expertise into software is it is necessary to have a deep understanding of both software development and the technology being computerized. In the welding industry, this includes metallurgy, engineering,production, quality control and standards. Standards are particularly important, as many aspects of fabrication are specified via national and international standards, such as ASME IX, AWS D1.1, EN 287/288 AND ISO 9000.
Software houses with no depth of welding expertise or engineers with no depth of software development skills both find it difficult to develop expert welding systems. It may be possible for individual engineers to develop software,but long-term support is difficult at best, and in most cases impossible. For storage of large amounts of information, where considerable time is invested in entering the data, long-term support is critical.
In addition, most existing software systems in the fabrication industry are tools for individuals, not for large parts of organizations, because, until recently, most organizations have simply not had the infrastructure to allow information to be distributed electronically. E-mail has helped change this. Electronic mail has driven most fabricators to use local and wide area networks. These networks make it possible to share welding procedures or welder approvals across a company via a multi-user software system.
Welding procedures and welder performance qualifications
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 long 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 applications.
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 knowledgebase 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 Weld spec 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.
An integrated software system such as Welding Co-ordinator can 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 completed 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 inorder 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 inspecting 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 sign 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 non prescriptive 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.
More information on Weldspec 4 can be found on the TWI Software pages (http://www.twisoftware.com/)