Reducing field rework is widely regarded as an effective way of improving construction performance in terms of productivity, cost, schedule, quality, and safety. While existing rework reduction programs and much literature exist concerning this challenge, there is a need for further analysis and continuous improvement of rework reduction methods. Based on such an analysis, this research develops a generalized conceptual model for a rework reduction program, which is intended to reduce rework by managing a continuous improvement loop with four functional processes: (1) rework tracking and cause classification, (2) evaluation of rework and its causes, (3) corrective action planning, and (4) integration of changes into the total management system. A case study is conducted to examine and verify the functional mechanisms and effectiveness of the generalized model, by investigating a rework reduction program implemented in practice that represents the generalized model, and by analyzing the impact trends on rework in terms of frequency, cost, and labor hours over a considerable time period. The results indicate that rework can be reduced significantly with such a program.

Reducing field rework is widely regarded as an effective way of improving construction performance in terms of productivity, cost, schedule, quality, and safety. While existing rework reduction programs and much literature exist concerning this challenge, there is a need for further analysis and continuous improvement of rework reduction methods. Based on such an analysis, this research develops a generalized conceptual model for a rework reduction program, which is intended to reduce rework by managing a continuous improvement loop with four functional processes: (1) rework tracking and cause classification, (2) evaluation of rework and its causes, (3) corrective action planning, and (4) integration of changes into the total management system. A case study is conducted to examine and verify the functional mechanisms and effectiveness of the generalized model, by investigating a rework reduction program implemented in practice that represents the generalized model, and by analyzing the impact trends on rework in terms of frequency, cost, and labor hours over a considerable time period. The results indicate that rework can be reduced significantly with such a program.

Design rework includes unnecessary repetition in design tasks to correct design problems. Resolving design matters in advance, through in-depth understanding of the design planning and rework issues and development of effective predictive tools could contribute to higher business profit margins and a faster product time-to-market. This research aims to develop three novel and structured methods to predict the design rework occurrence and effort at the very early design stage, which may otherwise remain undiscovered until the testing and refinement phase. The major contribution obtained from the Design Rework Probability of Occurrence Estimation method, DRePOE, is the development of design rework drivers. The developed drivers have been synthesised with data from interview results, direct observations, and archival records obtained from eleven world-class aerospace and automotive components manufacturers. To predict the probability of occurrence, the individual score of each driver was compared against historical records utilising the analogy-based method. The Design Rework Effort Estimation method, DREE, was developed to interconnect functional structures and identify failure relationships among components. A significant contribution of The DREE method is its capability to assess the design rework effort at the component level under the worst-case scenario. Next a Prioritisation Design by Design Rework Effort Based method, PriDDREB, was developed to provide a tool to forecast the maximum design rework given the constraint. This method provides a tool to determine and prioritise the components that may require a significant design rework effort. The three methods developed were validated with an automotive water pump, a turbocharger, and a McPherson strut suspension system in accordance with the validation square method. It is demonstrated that DRePOE, DREE, PriDDREB methods can offer the product design team a means to predict the probability of design rework occurrence and assess the required effort during the testing and refinement phase at the very early design phase.

The effect of time that processed cheese was held ex- posed to heat alone or with agitation, the level of rework cheese, and the type and level of emulsifying salt were evaluated by determining finess of emulsion based on scanning electron microscopy measurements, meltability, and rheological measurements using a Universal Testing Machine. Process cheese held in the cooker at 82°C for up to 4o minutes became less meltable and more firm and the emulsion became finer while that held at 82°C outside of the cooker without agitation was only slightly affected. Loss of meltability and increased firmness associated with pro-longed cooking of process cheese is associated with the state of the fat emulsion and not with the effect of heat on the proteins per se. The level of rework cheese had a great influence on the cheese rheological properties as well as on the microstructure of process cheese. There was a poor emulsion when no emulsifying salt was used regardless of the percent rework cheese added. The emulsion became finer as the per- cent rework cheese was increased if emulsifying salt was also present except after 20% rework cheese addition where the emulsion became coarse again. Process cheese lost meltability during storage at 4°C after 53 days when 1.0 or 0.0% emulsifying salt is used or when rework cheese is present at 0.0 or 5%, but no effect was noticed in meltability values if the 2.5% emulsifying salt was used with no rework cheese.

No / Transportation infrastructure projects are prone to cost and schedule overruns. At the time of contract award, a construction contingency budget is often used to accommodate for unplanned events such as scope changes. Recent empirical research has shown that rework during construction as a result of design changes, errors and omission are the major contributors of overruns in projects. The statistical characteristics of rework, and cost and schedule overruns that are experienced from a project's contract award for 58 Australian transportation infrastructure projects are analysed. Theoretical probability distributions are fitted to the rework, cost and schedule overrun data. Goodness of fit tests are used in conjunction with probability-probability (P-P) plots to compare the sample distribution from the known theoretical distribution. A Generalised Logistic probability density function is found to describe the behaviour of cost-overruns and provides the best overall distribution fit. The best fitting distribution for schedule overruns and rework data were the Four Parameter Burr and a Johnson SB distribution, respectively. The distributions are used to calculate the probability of rework, cost and schedule overruns being experienced. A case illustration is presented and discussed to demonstrate how the derived probabilities may be utilised in practice.

Yes / To make sense of the rework phenomena that plagues construction projects a longitudinal exploration and mixed-method approach was undertaken to understand its causal setting and why it remained an on-going issue for organizations contracted to deliver an asset. The research reveals that rework was an zemblanity (i.e., being an unpleasant un-surprise) that resulted in: (1) project managers ignoring established organisation-wide procedures and, at their discretion, amend them to suit their own goals while denouncing the importance of recording and learning from non-conformances; (2) a deficiency of organisational controls and routines to contain and reduce rework; and (3) an absence of an organisation-project dyad that supported and promoted an environment of psychological safety. A new theoretical conceptualization of error causation that is intricately linked to rework and safety incidents is presented. The research provides managers with ‘uncomfortable knowledge’, which is needed to provide insights into the determinants of rework that form part of their everyday practice. / Australian Research Council (DP130103018)

Taguchi defines quality loss as the loss imposed to the consumer for each unit of deviation from the target consumer requirements. In this thesis, the effects of inspection error and rework on quality loss are studied for a nominal-the-best type quality characteristic. The distribution of the quality characteristic in a production environment where there are inspection error and a separate rework facility is investigated. 100 % inspection policy is considered. After deriving the mean and variance of the resulting distribution of the quality characteristic, the true and simulated quality loss values for a number of scenarios are calculated. Furthermore, effects of deviation of the process mean from the target and variance of the rework are studied besides inspection error and process capability through a full factor factorial experimental design. Results are discussed for possible uses as quality improvement project selection criteria.

This diploma thesis handles with problems of reducing the production costs. The costs are connected with produce of scraps on Opel Delta project, where is the zero rework process booted. This work contains analysis of scraps for several periods and etablished actions to decrease inception of scraps.

The diploma thesis deals with reduction of scrapping at zero rework projects. These are the projects where corrections of particular parts are not allowed. If there are any in this way damaged parts, the entire products become scraps. Due to the fact the cost of low quality is increased, which is undesirable. The theoretical part describes the use of the six sigma method, which is then applied in the practical part. By using the IPO analysis the possible causes of the main problem have been chosen and then tested. The output of the diploma thesis is to find out and eliminate the causes of discrepancy, especially bridge walls at zero rework projects. After implementation of the first arrangements the scrapping has already been reduced.

No / There is growing demand for cost effective and reliable floating production systems to maximize marginal and new deepwater fields worldwide. Floating Production Storage and Offloading (FPSO) vessels are considered to be the most economical and viable options to meet this demand. Yet, FPSO projects are prone to significant cost and schedule growth. On average, FPSOs have been reported to experience a 20% cost growth and are delayed by six months. Overruns and delays represent uncertainties for owners, contractors and financial institutions. In-depth interviews with twenty-three practitioners about their experiences with FPSO projects revealed that rework arising from design and construction errors were major contributors to cost and schedule growth. Key latent conditions contributing to rework are classified according to people, organization and project. Using retrospective sensemaking an examination of the determinant histories in a new build and conversion FPSO that experienced rework was undertaken. The sharing of experience(s) is deemed pivotal for reducing rework in future projects, particularly through the use of communities of practice that are able to stimulate situated learning to take place. A reduction in rework will not only reduce cost and schedule growth, improve operational performance and augment safety.