Purpose: This paper studies how the concepts of efficiency, effectiveness and efficacy are used in project management literature. The concepts relate to the degree of success or failure of projects and the degree to which the results are achieved. The purpose of this paper is to review the use of the concepts of efficiency, efficacy and effectiveness in project management literature and among practitioners. Design/methodology/approach: The study is based on an extensive literature review, initially from the International Journal of Managing Projects in Business. The first phase involved searching the words “efficiency”, “effectiveness” and “efficacy” in all articles of the journal, and then quantifying the results. This was followed by a qualitative search of the same articles with the aim of understanding how the terms “project efficiency”, “project efficacy” and “project effectiveness” are used. A further intensive literature review was then conducted in other literatures in the field of project management, including, but not limited to, International Journal of Project Management and Project Management Journal. Finally, the authors complemented the review by including theories from deep searches of Google Scholar and Google Books using the parameters “project efficiency”, “project effectiveness” and “project efficacy” and checked how the three concepts are used in other fields. Findings: This research reveals there is wide diversity in interpretations of the three concepts among research scholars and practitioners, which makes it challenging to apply these three concepts appropriately and clearly. As a consequence, the authors propose a model for describing these concepts. Research limitations/implications: This research is based on an academic and non-academic literature review. It identifies a number of inconsistencies in existing literature regarding the three concepts. Practical implications: This review enriches understanding of project management. Clarifying the understanding of project efficiency, project effectiveness and project efficacy will help and support organisational improvement. A clear and aligned view of these concepts can also be a basis for measurements based on possible developed indicators. Originality/value: This paper highlights the gap in the literature concerning the practical use and interpretation of the concepts “project efficiency”, “project effectiveness” and “project efficacy”.

Clay is of great interest as a 3D printing material thanks to its ease of use, recyclability and reusability. This paper analyses the technical aspects of the whole printing process. The behaviour of 3D printing clay is studied with respect to the environment and its specific application as a temporary or definitive formwork system for cement parts. The study addresses the performance of clay and the loss of its properties and characteristics according to the type of protection, whether it is in direct contact with air or cement, or protected with plastics, metal sheets, or combinations of both. A 3D printing system with various printers and 3D models has been considered, observing a direct relationship between the prototype shape, extrusion process and resulting material. The most important variables in 3D printing have been considered: layer height, line thickness, base definition, total model height, overhang angles, overlap between layers, etc. The main technical aspects have been analysed such as raw material properties, kneading, process control, post-treatments and material hardening. As a natural material, clay can be reused indefinitely under certain conditions to be part of a circular economy with low energy consumption and minimal resources. It is concluded that the option of using ceramics in 3D printing for very diverse uses in the architecture, engineering & construction (AEC) sector is very promising due to their ease of implementation, recycling capability and suitability to different environments.

Objective: This paper analyzes the dynamics relating to flexibility in a hospital project context. Three research questions are addressed: (1) When is flexibility used in the life cycle of a project? (2) What are the stakeholders' perspectives on project flexibility? And (3) What is the nature of the interaction between flexibility in the process of a project and flexibility in terms of the characteristics of a building? Background: Flexibility is discussed from both a project management point of view and from a hospital architecture perspective. Flexibility in project life cycle and from a stakeholder perspective is examined, and the interaction between flexibility in scope lock-in and building flexibility is investigated. Methods: The results are based on case studies of four Norwegian hospital projects. Information relating to the projects has been obtained from evaluation reports, other relevant documents, and interviews. Observations were codified and analyzed based on selected parameters that represent different aspects of flexibility. Results: One of the cases illustrates how late changes can have a significant negative impact on the project itself, contributing to delays and cost overruns. Another case illustrates that late scope lock-in on a limited part of the project, in this case related to medical equipment, can be done in a controlled manner. Project owners and users appear to have given flexibility high priority. Project management teams are less likely to embrace changes and late scope lock-in. Architects and consultants are important for translating program requirements into physical design. A highly flexible building did not stop some stakeholders from pushing for significant changes and extensions during construction.

The construction industry has embraced digitisation and industrialisation in response to the need to increase its productivity, optimise material consumption and improve workmanship. Additive manufacturing (AM), more widely known as 3D printing, has driven substantial progress in these respects in other industries, and a number of national and international projects have helped to introduce the technique to the construction industry. As with other innovative processes not covered by uniform standards, appropriate assessments and testing methodologies to control the quality of the 3D-printed end products, while not obligatory, are advisable. This article shows that regulation is not an obstacle to the use of an innovative product, such as 3D printing, by proposing quality-control tests and an assessment methodology, in the understanding that standardisation ensures the viability of a technology. The information, including the methods and results, is based on the authors’ experiences in the development of three research projects pertaining to 3D printing. This paper also discusses whether the performance of the materials used in 3D printing could be superior to traditional ones.

This article elaborates on lean thinking in design management. Lean philosophy focuses on minimizing waste and maximizing value. We discuss how lean concepts can be understood and how this can affect the design process. In particular, we examine how flexibility can be achieved through the use of a layered design process and a layered building design. The design process has two main outcomes: input to the production and/or construction process, and input to the decision process. These two outcomes have a number of contradictory characteristics. Traditionally, production processes call for early decisions and control of cost, time and risks. Typically, this has been the engineers’ or the contractors’ perspective. In contrast, the decision process typically strives to postpone final commitments and design freeze in order to keep options open. Lean thinking shows that the two approaches do not have to be contradictory. Based on case studies of two hospital projects, we discuss flexibility in the design process and design in relation to lean principles. The article demonstrates the importance of seeing the design process and design model as two integrated parts. Lean thinking can serve as an enabler by focusing on reducing waste and increasing the customer's value.