The definition of fabrication is the process of making something from semi-finished or raw materials rather than from ready-made components. Commercial fabrication is the shop assembly and construction of the engineered equipment as designed and as approved by the client. It usually includes the coordination of a multitude of vendors and sub-suppliers to achieve the desired result of integrating all items into a ready for shipment package. Fabrication may be performed directly by the provider of equipment or outsourced to a qualified facility. Fabrication projects typically range from tens of thousands of dollars to millions of dollars. They are frequently performed for a client or an engineering, procurement and construction company that represents a client’s interest.
A successful fabrication project requires a strong engineering design, drawing execution, and subsequent building and integration of the equipment. To ensure the project is executed successfully requires a good understanding of shop load, appropriate outsourcing partners, propoer communication, and QA/QC functions.
By the time equipment has reached the fabrication stage, it is a matter of executing the construction plan that has been largely agreed upon with the client at contract award. Key features to a construction plan include which items or components will be built in an equipment supplier’s shop, which items will be outsourced to an approved subcontractor or facility, and at which locations final assembly and testing will take place.
Keys to a Successful Project
When determining which items will be fabricated in-house, plotting and maintaining a shop loading chart is essential. A fabrication facility will typically be working on numerous equipment orders at once, and the fabrication team must maintain constant diligence in their planning efforts in order to maintain flexibility to adjust to dynamic project developments and scheduling requests, and also to maintain high shop utilization and productivity. A representative shop loading chart plots available man-hours expected for projects worked during that time against each other. In most shop environments, much more detail is required depending on the particular situation regarding aspects of the shop layout, efficient workflow and materials management, contractual obligations and milestones, critical fabrication sequencing requirements, and a shop or facilities ability to stage or store equipment at various stages of completion.
As a standard, the fast-paced nature of engineered equipment drives the fabrication process to be rapid. Engineered equipment will invariably have revisions to drawings and is typically resource constrained. Drawing approval delays or incorrect drawings can have critical consequences.
The supplier will often be pushed to partially release drawings as they become complete. A partial release of drawings is defined as a full set of drawings for a particular component prior to the completion of the drawings for all components on the project. Partial release pressure is either done to keep schedule or meet revenue milestones. While partial releases are often unavoidable, they can create inefficiency and confusion if not managed properly.To understand how partial releases should be handled, the project manager, plant manager, and scheduler must be in full alignment prior to any partial release decision.
Effective use of subcontractors and third-party facilities can often be a useful method of relieving some of these constraints and pinch-points within internal shop capabilities and capacities, and still allow the meeting of both individual project goals and maintaining high internal fabrication shop efficiency. Third-party facilities and subcontractors typically require client approval.
For equipment built at another facility, the equipment provider must exercise a heightened level of diligence to ensure that the supplier’s quality standards are being equaled or surpassed at the subcontractor’s facility. As such, any purchase orders to the sub-suppliers must include applicable specifications and criteria for a successful project.
Quality is a functional department, but also an attitude that should permeate the entire process. There are two branches of Quality – Quality Assurance and Quality Control. Quality Assurance is quality applied to the fabrication process to ensure the methods of fabrication are correct and optimized. Quality Control deals with ensuring quality goods are produced. Quality Control is a joint effort between the supplier and client and follows the inspection and test plan (ITP) laid out during the engineering and procurement phase of the project. The proper administration of a quality plan can save the project thousands of dollars in rework and help ensure projected deliveries are met.
There are several ways that fabricators artificially push activities onto the critical path that should be far removed from that path. Delays in giving the client weld procedures are weld maps are unfortunately common. Another major issue is a disjoint between the supplier’s engineering team and fabrication team. This is exacerbated when the engineering and fabrication team operate out of different facilities.
Carbon steel and stainless steel are standard metals for fabrication purposes and most shops will have weld procedures in place for the handling and fabrication of these materials. Stainless steel must be carefully segregated from carbon steel or cross contamination may occur. Materials outside of stainless and carbon are considered exotic metals and different welding approaches must be undertaken.
A typical ITP shows the different fabrication steps and the hold, inspection, and witness requirements for each step. It is crucial that all stakeholders are aware of the ITP as readiness notification are typically required 5-10 business days in advance so that travel and accommodations can be planned accordingly.
During the fabrication process, expeditors will often become involved. An expeditor’s job is to get critical information by any means necessary. The expeditor’s role is to illuminate areas that do not appear to be in sync with reality and require recovery plans and commitments if deliverables are in jeopardy of missing their previously agreed deadlines.
Once fabrication and integration is complete, the job enters the functional acceptance (FAT) stage. The FAT ensures instrumentation performs as designed and the control schema is in proper place. The FAT involves the equipment provider, any subvendors, as well as the client and engineering firms, if applicable. Any errors noticed during the FAT are put on a punchlist and must either be corrected prior to shipment or have a plan in place for corrections to be made.
By Michael Nasser of Punchlist Zero