Abstract
The estimation of man-hours required to construct highly complex constructions such as buildings or steel facades is often very speculative [1] and frequently based on the experience of single personnel staff. The most common method of estimating time and costs for manufacturing activities is the industrial approach. Using this approach process times are established for the single operations in the manufacturing process. In the ETO (Engineer-to-order) sector and even more in the high-level construction sector usually every project is different from each other. Because of the low repeat frequency of similar or equal building elements and the high variance of manufacturing processes most of the companies in this sector are not able to install a solid production planning and control. Therefore reliable cost estimation and time scheduling is very difficult to define and causes quite often high uncertainty and budget overrun. This paper presents a methodology to determine manufacturing process times in the ETO sector by the use of different categories of process times. The aim of the methodology is to reduce the effort for a more detailed planning of the production processes. The elaborated methodology was successfully proven on a real case study in a North-Italian façade construction company.