Additive manufacturing in the mechanical engineering and medical industries spare parts supply chain
Authors: Muir Melanie , Haddud Abubaker 
Published: December 2017

Purpose
The purpose of this paper is to approximate the impact that additive manufacturing (AM) will have on firm inventory performance (IP) and customer satisfaction (CS) when it is applied within the spare parts (SP) supply chain of manufacturing organisations. This research also explores the influence of customer sensitivity (CSy) to price and delivery lead time and supply risk (SR) within those approximations.

Design/methodology/approach
An online survey was used to collect the primary data for this research. Data were collected from 69 respondents working for organisations in two industrial segments within the UK manufacturing sector: “Industrial and Commercial Machinery and Computer Equipment” and “Measuring, Analysing and Controlling Instruments, Photographic, Medical and Optical Instruments”. The respondents worked for entities that were categorised in three groups: customers, suppliers, and entities that were both customers and suppliers. The groups that were self-identified as “customers” or “suppliers” answered 20 survey items each and the group that was identified as both “customers” and “suppliers” answered 40 survey items.

Findings
The results revealed that AM was considered a suitable vehicle for the fulfilment of SP demand. However, AM appeared to make no material difference to CS; the scenario used improved delivery time of SP but increased price. Also, AM was thought to improve IP through less reliance on buffer stock to manage SR and spikes in demand and less carrying of SP at risk of obsolescence.

Research limitations/implications
The respondents worked for entities within two manufacturing industry segments within the UK and the insights garnered may not be indicative of similar organisations competing in other manufacturing industry segments within the UK or in other countries. In addition, approximately 82 per cent of the surveyed respondents worked for small organisations with fewer than 100 employees and the results may differ for larger organisations. Further limitations were the relatively small sample size and lack of open-ended questions used in the survey. Larger sample size and the usage of open-ended survey questions may lead to more reliable and valuable responses and feedback.

Practical implications
The findings from this research are considered to be of interest to practitioners contemplating adoption of AM and to developers of AM wishing to increase market share due to the positive reaction of entities within the industrial and commercial machinery and computer equipment, and measuring, analysing and controlling instrumentation industrial segments. This research raises awareness to the possible risks and rewards – from a range of perspectives, of AM to practitioners considering its adoption in the spare parts supply chain (SPSC).

Originality/value
The paper takes a novel perspective on AM in SPSCs by illuminating the supplier and buyer perspective based on empirical data. This research provides new insights about the appreciation of the use of AM in SPSCs of mostly small sized manufacturing companies located in the UK. This paper also gives new insights about the willingness/conditions of manufacturing companies in the UK to adopt AM for the provision of SP. The originality of this research is twofold: it broached the applicability of AM in the supply chains of the two targeted industrial segments, and as far as the authors are aware, the influence of CSy (e.g. to price or lead time) and SR on SPSC players’ attitude to AM is yet to be considered. Finally, this research adopted a systems theory lens and considered system-wide impact of AM introduction.