Improvement of maintenance-based Product-Service System offering through field data: a case study

Figures & data

Figure 1. Methodology for the analysis of field service maintenance reports.

Table 1. Pseudocode for analysis.

READ dataset GET column of interest FOR each document (row) in the selected column DETERMINE language IF language IS NOT English THEN Translate to English ELSE Go to next row END IF REMOVE punctuation FOR each token (word) in the selected document SET token lowercased READ token IF token is translated in a wrong way THEN SET token to correct form ELSE Move to next token END IF IF token is present in the list of stopwords (Stopwords removal) THEN REMOVE token ELSE Go to next token END IF SET token to its root form through (Lemmatization) ASSIGN part of speech tag to each token (Part of speech tagging) CONVERT document content into a numerical vector FOR each token in the document ASSIGN a weight using TF-IDF approach REMOVE tokes with a weight under a certain threshold END FOR SET number of topics and other parameters for the Latent Dirichlet Allocation (LDA) algorithm CALCULATE topic content with LDA algorithm IF topic content is acceptable THEN SAVE model APPLY model to dataset to assign topics to each document ELSE COMPUTE preprocessing again with the required modifications SET new number of topics or other parameters for LDA algorithm CALCULATE topic content with LDA algorithm END IF

Figure 2. Distribution of interventions per technician.

Figure 3. Number of reports filled per year by the top six technicians.

Figure 4. Distribution of interventions per a) nation, b) technician, and c) year.

Figure 5. Topics occurrences in the dataset.

Figure 6. Topic trends over the years. The bigger the marker, the higher the number of interventions.

Figure 7. Topic co-occurrence.

Figure 8. a) co-occurrence between topic and technician and b) distribution of topics among the four models with more interventions.

Table 2. Topic content.

Topic	Keywords	Topic description
Air_Valve	mold, air, pressure, filter, valve, blow, bearing, bottom, replace, overhaul	This topic refers to problems related to the production of bottles. It relates to the bottle-blowing process and the air valve functioning.
Belt	replace, chain, engine, belt, part, good, transport, gate, format, several	This topic refers to problems with the transportation belt and the components that are used to make it work.
Bottle	speed, bottle, increase, unit, filler, blow, reform, let, much, use	This topic refers to problems related to the filling process of the bottles and their transportation. It differs from the ‘Belt’ topic because it focuses on bottles that may fall and interrupt the flow, not on problems related to the transportation belt and the related mechanism.
Communication	cable, communication, oven, alarm, belt, perform, connection, damage, signal, connect	This topic refers to problems related to the components that allow the asset subgroups to communicate between them and to the ones that allow the asset to communicate with the cloud. It does not consider the optical fiber component which is another topic.
Film/Format	film, format, parameter, control, engine, set, position, cut, separate, two	This topic refers to problems related to the packaging process, which varies depending on the bottle format.
Optical_Fiber	replace, ring, check, optical_fiber, device, fiber, island, part, one, type	This topic refers to problems related to the optical fiber that is used to put in communication the terminals, and components of the asset. Given that some interventions are executed specifically on this, a topic separated from the communication one was identified.
Oven	check, run, oven, one, system, phase, error, camp, order, temperature	This topic refers to problems related to the oven that is used to warm the bottles in the production process.
Sensor	think, dummy_bottle, accumulation, photocell, location, membrane, fuse, emergency_button, burn	This topic refers to problems related to the sensor that has to check the accumulation of bottles in specific parts of the asset.
Terminal	terminal, program, version, part, drive, terminal, console, communication, update, switch	This topic refers to problems related to the terminals that are installed on the asset to make it works and control production parameters.
Various	issue, publication, know, address, automatic, bag, flap, little, adjust, upper	This is a generic topic that covers all the other problems that were not that frequent to create a specific topic.

Table 4. Additional general improvements achievable through field data analysis.

Area	General improvement
Asset	Identify design problems and induce components’ redesign. Failure clustering according to the lifecycle (e.g. infancy vs wearing). Geographical-based analysis to check connections between failures and environmental conditions, useful to redesign components accordingly.
Field Service Maintenance	Re-engineer the field service maintenance delivery process, both improving the efficiency and effectiveness of the process itself Enable new field service maintenance provision modes (e.g. remote support).
Technician	Understand the skills owned by each technician, as well as their level, to assign interventions and define improvements. With time-based analysis, gain further insights into the technicians’ performance and skills.
New services	Analysis topics vs customers may reveal additional services to offer depending on the interventions’ content, frequency, and evolution. Analysis of spare parts consumption to improve their sales according to contextual conditions.

Table 3. Improvements were achieved following the NLP analysis for the case of company A.

Area	Company A improvement
Asset	Identified the cause of common ‘communication’ problems. Model_02 assets had major ‘Oven’ and ‘Film_Format’ problems. Redesign of the components solved the problems.
Field Service Maintenance	Identified a specific problem affecting multiple models of its portfolio (i.e. communication) and provided technicians with instruction to solve the problem optimally, reducing the time required to execute field service maintenance and increasing its effectiveness and efficiency. When executing a maintenance intervention always check communication components to ensure correct data sharing with the cloud and on the machine (new troubleshooting procedure).
Technician	Improvement paths for the technicians based on the intervention history defined (i.e. five out of the top 6 technicians considered in the analysis are strongly focused on interventions related to Oven, Film/Format, and Communication. Other training might be provided). Periodic skill checks planned to maintain the benefits of the improvements.
New services	Since a recurring problem with the format produced by the asset due to wrong regulations made by the customers has been noticed, training on the parameters’ regulation was offered. Additional consultancy and training are offered to some customers. Communication components redesigned to avoid frequent failures and guarantee reliable data transmission to allow reliable remote services.