The construction industry of Ukraine has a number of problems and barriers that hinder its development. The main problems affecting Ukraine are corruption, high level of opacity, inefficient use of resources and inefficient process management. Moreover, ineffective design and construction management reduce labor productivity and leads to reworks. Unfortunately, in Ukrainian construction industry most cases of rework have been accepted as a part of construction activities. Rework is one of the main factors in the growth of total costs and the excess of the schedule for the construction project. The problem of rework costs is important and needs to be studied more to alleviate these overruns in the future. However, rework data are usually quite difficult to obtain and most studies have been conducted in developed countries. It can be assumed that there is a greater probability of reworks and rework costs in developing countries than in the developed ones. Thus, the purpose of this article was to determine and systematize reworks factors, quantify amount of direct rework costs, determine the relationship between actual project costs, project duration variation and rework costs.

The collapse of the Soviet Union was the cause of a significant decline in many economies of the newly created countries. However, many of them, including the Ukrainian economy, are slowly recovering. One of the largest branches of the economy in this country is construction, which, despite political turmoil, is constantly growing, especially in the private real estate development sector. Despite the fact that the construction market is constantly developing, it is limited by the costs of rework and alterations resulting from many reasons. The key negative effects of modifications to the results of the project are exceeding the budget and time of project implementation, dissatisfaction with the project team, violation of contractual requirements and lowering the quality of the final product. Therefore, the purpose of this article was to determine the reasons for the emergence of rework in the in Ukraine by analyzing the results of surveys conducted among construction enterprises.

Waste or additional costs in infrastructure projects such as jetty projects are often caused by rework. Besides having an impact on costs, rework is also a very significant contributor to waste or adding time which causes delays in the completion schedule of the project. A lot of research on rework has been carried out on both building and road construction projects, but there is no jetty construction project. This study aims to develop improvement scenarios to minimize the emergence of rework on pier infrastructure projects by modelling and simulating cost performance. The research variables were obtained based on the results of a literature study by asking for opinions from experts who are compatible in their scope. The initial model used the causal loop diagram form which was later developed into a Stock Flow Diagram, after which a repair simulation was carried out using the dynamic system method to determine the effect on cost performance. From the research results obtained 14 factors that affect the cost and time performance on the jetty project, the implementation of a dynamic system can provide the optimum solution with the ability to reduce the percentage of the number of reworks by 24.12% for 12 months.

To increase their competitive advantage in turbulent marketplaces, contemporary manufacturers must show determination in seeking ways to: fulfill buyer orders with quality merchandise; meet deadlines; handle unexpected production disruptions; and lower the total relevant expense. To tackle the abovementioned challenges, this study explores an economic manufacturing quantity (EMQ) model with machine failure, overtime, and rework/disposal of nonconforming items; the goal is to find the best fabrication uptime that minimizes total relevant expenses. Specifically, we consider a production unit with overtime capacity as an operational feature that is linked to higher unit and setup costs. Further, its EMQ-based process is subject to random nonconforming items and failure rates. Extra screening separates the reworkable nonconforming items from scrap, and the rework is executed at the end of each cycle of regular fabrication. The failures follow a Poisson distribution, and a machine repair task starts as soon as a failure occurs; the fabrication of the lot that was interrupted resumes after the repair has been carried out. A decision model is built to capture the characteristics of the problem. Mathematical and optimization processes help in determining the optimal fabrication uptime. A numerical example not only illustrates the applicability of the research outcomes, but also reveals a diverse set of information about the individual or joint influences of deviations in mean-time-to-failure, overtime factors, and rework/disposal ratios linked to nonconforming rates related to the optimal replenishment uptime, total operating expenses, and various cost contributors; this facilitates better decision making.