Implementation of lean in health care environments: an update of systematic reviews
Authors: Lima Rui M. , Dinis-Carvalho José , Souza Thiago A. , Vieira Elisa , Gonçalves Bruno 
Published: July 2020

Purpose
Even though the implementation of lean in health care environments is relatively recent, it has been receiving a lot of attention in recent years. Partly because of the fact that it is a recent field of practise and research and partly because the number of works developed in this field has grown rapidly, it is important to frequently update the perspectives on this field of investigation. Thus, this study aims to review the implementation of lean tools and techniques applied to hospital organizational areas in a five-year period, between 2014 and 2018, complementing some of the most relevant reviews already published. The most important criteria such as tools, methods and principles, hospital areas intervened, improvements and difficulties were assessed and quantified.

Design/methodology/approach
As starting point for this systematic literature review (SLR), a set of selected pre-existing review publications was used to support the current study and as the ground base for the expansion of the studies about lean health care. The current study contemplated 114 articles from a five-year period between 2014 and 2018. A subset of 58 of these articles was critically assessed to understand the application of lean tools and methods in different hospital areas.

Findings
The thorough analysis of selected articles show a lack of works in continuous improvement approaches when compared to the application of production organization methods, visual management and diagnosing and problem-solving tools. The reported improvement results demonstrate alignment with the principles and foundations of lean philosophy, but such results are presented in isolated initiatives and without robust evidence of long-term maintenance. Moreover, this study shows an evolution in the number of articles referring to lean implementation in hospital areas, but in its great majority, such articles report isolated implementations in different areas, not spreading those for the global organization. Thus, some of the main recommendations are the need to implement studies on complete flows of patients, drugs and materials, instead of isolated initiatives and strive to promote the cultural change of hospitals through structural changes, following new visions and strategic objectives, supported by real models of continuous structural and sustained improvement.

Originality/value
The current study develops a new perspective of the articles published under the thematic of lean health care, published in a recent period of five years, which are not completely covered by other works. Additionally, it explicitly applied, in an innovative way, an approach that used a set of previous reviews as the starting point for this SLR. In this way, it integrates approaches and categories from different SLRs, creating a framework of analysis that can be used by future researchers. Finally, it shows the most recent implementations of lean health care, exposing the current trends, improvements and also the main gaps.