Anna Ericson Öberg

The Subjective Judgement of Weld Quality and Its Effect on Production Cost

The focus is often on new material, improving weld methods or increased automation when cutting production costs within the welding industry. However, the way the quality inspection is conducted can as well cause not negligible production costs.

Facilitating decision-making by choosing an NDT method based on information need

This paper discusses the choice of an NDT method (non-destructive testing) from an information need perspective. It bridges the gap between technical methods, monitoring procedures and the need for information in an industrial application. The simple pull approach described starts from the decision that needs to be taken rather than from a previous data push procedure. That makes it more likely to match the method with the actual need, which leads to more effective and efficient evaluations. The pull approach is described by using a case from the welding industry, evaluation of the weld toe radius. The toe radius, defining how smooth the transition between the plate and the weld is, has been found critical to fatigue strength. Depending on the internal customer’s need of information, various evaluation solutions are preferred. The methods range from manual gauges to fully automated camera solutions. An interview study performed shows that the current process for choosing evaluation method differs. The person needing the information is often not the starting point in the process. A change in starting point influences both the choice of NDT method and visualization and thereby how efficient and effective the decision-making support will be. The financial effect is significant.

Cost Affecting Factors Related to Fillet Joints

Fillet welds are by far the most frequent arc welding joint type in the fabrication industry with about 80% of all arc welded joints worldwide. Although the joint is well established, there are many aspects to consider when producing an ideal weld. This paper reveals and connects several problematic issues related to the joint type and the difficulties to fabricate a weld with correct strength, cost, and quality.

Prediction of penetration in one-sided fillet welds by in-process joint gap monitoring : an experimental study

The challenge to predict variations in penetration depth in one-sided fillet welds during robotized gas metal arc welding has been addressed by a pilot investigation of technical possibilities and limitations. The main cause for the variation in penetration depth is considered to be variation in joint gap size. Special attention has been paid in order to adopt the experimental conditions to conform to industrial welding conditions. The employed method uses in-process monitoring of joint gap size together with an empirical model relating penetration depth to gap size in order to predict this depth. The gap size estimates are based on image information from two cameras, one visual and one infrared. The results, that are evaluated off-line, confirm the development of a real-time method providing technical solutions that are industrially tractable. The results also pinpoint areas of further improvements towards increased robustness and reduced estimation uncertainties.

Factors influencing control charts usage of operational measures

Purpose The purpose of this paper is to identify factors influencing implementation of control charts on key performance indicators (KPIs). Design/methodology/approach Factors driving organizational change described in literature are analyzed inspired by the affinity-interrelationship method. A holistic multiple-case design is used to conduct six workshops to affect the usage of control charts on KPIs at a global company in the automotive industry. The theoretical factors are compared with the result from the case study. Findings The important factors for implementation success differ to some extent between the theoretical and empirical studies. High-level commitment and a clear definition of the goal of change could be most important when creating a motivation for change. Thereafter, having a dedicated change agent, choosing an important KPI and being able to describe the gain in financial terms becomes more important. Practical implications By using control charts on KPIs, the organization in the case study has become more proactive, addressing the right issues upstream in the process, in the right way, cross-functionally. Originality/value Factors affecting the implementation of already available solutions in the industry are highlighted. This potentially provides a basis for improved decision making, which has a significant value.