Link Analysis (LA) is a useful method to study relationships and arrangements of
elements within a system. It has been used more and more in the healthcare domain
to create appropriate work conditions for clinical staff and provide patients with
effective, efficient and safe services. However LA has limitations, such as the timeconsuming
manual data recording and results generating processes. Thus, the
Computerised Link Analysis (CLA) system was developed and is being tested to
provide flexibility by computerising template generation, and data collection and
analysis processes. This paper will describe the development and iterative testing
(technical, usability and field) of the CLA system

Neil Mansfield (1252779)

Sue Hignett (1249203)

Yu Zhao (104852)

English

Crossref

Computerised Link Analysis

Loughborough University Institutional Repository

   This item was submitted to Loughborough’s Institutional Repository (https://dspace.lboro.ac.uk/) by the author and is made available under the following Creative Commons Licence conditions.      For the full text of this licence, please go to: http://creativecommons.org/licenses/by-nc-nd/2.5/     Computerised Link Analysis Yu Zhao, Sue Hignett, Neil Mansfield  Department of Ergonomics Loughborough University, UK  ABSTRACT Link Analysis (LA) is a useful method to study relationships and arrangements of elements within a system.  It has been used more and more in the healthcare domain to create appropriate work conditions for clinical staff and provide patients with effective, efficient and safe services.  However LA has limitations, such as the time-consuming manual data recording and results generating processes. Thus, the Computerised Link Analysis (CLA) system was developed and is being tested to provide flexibility by computerising template generation, and data collection and analysis processes.  This paper will describe the development and iterative testing (technical, usability and field) of the CLA system.   INTRODUCTION Link Analysis (LA) is a useful ergonomic method in layout and task design.  In Link Analysis, systems are composed of components and links.  Components comprise items in the system (for example, chairs and tables in an office), while links are represented by the interactions between components, such as hand, eye or body movements.  The purpose of LA is to capture these interactions and attempt to produce an improved layout of workspace by rearranging components to achieve a minimum of overall link distance, in order to increase efficiency.  LA has been increasingly employed in the healthcare industry to improve layouts and enhance performance (Hignett & Lu, 2007; Jones, Hignett & Benger, 2008; Ferriera & Hignett, 2004).  Currently, the majority of researchers are still using a traditional ‘pen and paper’ method of LA.  This is labour-intensive and time-consuming as   researchers have to observe a task carefully while trying to record every interaction by drawing line between components on a link diagram, and then calculate the link frequencies by counting the lines on the diagram.  These data (link frequency in link table and interaction map in link diagram) have limited usefulness, as more parameters (e.g. link directions, chronological orders, time durations, etc) are required to take account of complex tasks, especially tasks in the healthcare domain.  Due to these limitations, a Computerised Link Analysis (CLA) system has been developed (Zhao, Hignett & Mansfield, 2009) and tested to provide researchers with an enhanced software tool to reduce the workload and save time and resources.  This paper will describe the development and iterative testing (technical, usability and field) of the CLA system.   COMPUTERISED LINK ANALYSIS (CLA) SYSTEM As techniques develop many achievements of simplifying the method of LA have been documented, such as Computer-Aided Link Analysis system (Glass, Zaloom & Gates, 1991), Link Analyzer system (Thorstensson, Axelsson, Morin & Jenvald, 2005), etc.  However, none are able to either capture and analyse real-time data effectively and efficiently, or were designed especially for use in the healthcare industry.  Thus, the Computerised Link Analysis (CLA) system has been developed and tested to provide analysts with an efficient and effective tool which integrates computerised layout creating, real-time data recording and real-time results generating processes.  The system consists of two applications, the Template Generator (TG) and Data Recorder (DR).  The TG is used to develop user-specified 2-D layout design, in which components are represented by rectangular boxes.  The purpose of the DR is to read in the layout, collect interactions in real-time, and generate LA results instantly.  The benefits of CLA are: • Reduction in time and resources required compared with the traditional LA method, as interactions/links are recorded simply by selecting the rectangular boxes in the layout according to the naturalistic operations; • Increased data analysed, such as chronological order, time duration and direction of links.   Early versions of CLA were tested for accuracy, usability and real-time ability, etc. in Technical Validation and Usability tests.   TECHNICAL VALIDATION TEST Technical Validation aimed to ensure the CLA system worked technically and achieved acceptable accuracy.  This test was conducted using previous LA studies with a range of different complexity tasks.  Comparisons were made between results of CLA and the manual results (obtained from previous reports) to assess its accuracy.     METHOD This test was conducted in two stages, Stage 1: previous study of assessing the reproduction of a two-sided document using a photocopier (Whitehead, 2008), which consisted of approximately 10 links; Stage 2: ambulance patient compartment (Thorne, 2008) was re-evaluated in CLA system using video clips of clinical staff simulating patient (mannequin) treatment in a ambulance mock-up. Comparisons were made between manual results and CLA results.    RESULTS Stage 1: As there were four participants in the previous report, four sets of comparisons were made on both link tables and link diagrams.  Two sets of CLA results out of four (including link tables and link diagrams) were identical with manual results (Participant A and C).  Although results of Participant B & D from two methods were slightly different, results of the CLA system were proven to be correct after Trial B & D was repeated using both traditional pen and paper method and CLA method (tables 1, 2, 3; figure 1).  Table 1 Photocopying activities of Participant D (adopted from Whitehead (2008)). STEP ACTION CODE 1 ‘Original’ document placed in feeder tray D 2 Presses ‘ON/OFF’ button (machine powers up) A 3 Finger hovers over LCD screen J 4 ‘Two-sided’ button pressed E 5 Finger hovers over LCD screen J 6 ‘2 > 2-Sided’ button pressed F 7 ‘OK’ button pressed G 8 ‘START’ button pressed (Document in feeder is drawn into the machine, document copied and copy plus original dispensed) B    Table 2 Link tables for Participant D, manual result (Whitehead, 2008).  Numbers in red and underlined are not correct; the correct ones are shown in Table 3 CLA result.  (A: On/Off; B: Start; C: Cancel; D: Feeder Tray; E: ‘Two-sided’; F: 2 > 2-sided; G: OK; H: Paper Select; I: Special Features; J Hover/Scan/Move Finger Away; K Lid)                 Table 3 Link tables of Participant D, CLA result   A                               B                               C         D                        E                F        G                 H                 I       J                       K         A                               0 0 0 0 0 0 0 0 0 0 0B                               0 0 0 0 0 0 0 0 0 0 0C                               0 0 0 0 0 0 0 0 0 0 0D                               1 0 0 0 0 0 0 0 0 0 0E                               0 0 0 0 0 0 0 0 0 0 0F                               0 0 0 0 0 0 0 0 0 0 0G                               0 1 0 0 0 1 0 0 0 0 0H                               0 0 0 0 0 0 0 0 0 0 0I                               0 0 0 0 0 0 0 0 0 0 0J                               1 0 0 0 2 1 0 0 0 0 0K                               0 0 0 0 0 0 0 0 0 0 0    A B C D E F G H I J K A            B            C            D 1           E            F     1       G  1    1      H            I            J 1    1 0      K               (a) The line with cross should be removed                (b) Correct result FIGURE 1  Link diagrams of Participant D. (a) manual method (b) CLA method Stage 2: One simulation scenario with two clinical staff was assessed and two sets of comparison on link tables were obtained.  Activities of Staff 1 registered using two methods were the same, however, there were some differences in results for Staff 2 (tables 4 and 5).  It was concluded that the link table generated by the CLA system was correct.    Table 4 Link table Staff 2 (CLA result).  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 181 Paramedic 62 patient 16 13 Oxygen tap 24 Work top5 Defibrillator 15 1 16 Work-top 27 Clinical waste bins 28 sharps bin9 High level cabinets10 Worktop 3 111 Bag on floor 312 Suction unit 13 Chair114 Responder bags 1 115 Chair216 Chair317 Another staff 7 118 High level cabinet 2 ×   Table 5 Link table Staff 2 (manual result; Thorne, 2008)  1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32Paramedic/technician 6*Patient 17 1*Oxygen tap 2Worktop1Defibrillator 15 1 1*Worktop2 2Clinical waste bins 1Sharps binHigh level cabinetStretcherBulkhead worktop 2 1Responder bag on bulkhead worktopResponder bag on floor 3Responder bag in cabinet 1 1Respionder bag on chairResponder bag on attendant chairResponder bag on stretcheritem placed on floorItem placed on chairitem placed on attendant chairSecond paramedic/technician 7Third paramedic/technicianDrugs safeDrugs bag in cabinetDrugs bag on floorDrugs bag on bulkhead worktopDrip hung upSuction UnitHigh level cabinet2 1Bulkhead doorLeft ambulance via back doorPhone at bulkhead  The Technical Validation test was successful and it was concluded that the CLA system, both TG and DR applications, operated reliably and accurately throughout validation test, and was capable of recording and analysing data in real time. USABILITY TEST The Usability Test aimed to identify improvements and bugs of the CLA system to both reduce the probability of failure/deficiency and increase reliability/usability.  12 users with various backgrounds (for example, Ergonomics, Computer Sciences, etc.) were invited to operate the CLA system in a laboratory environment. Virzi (1992) suggests that 65% of usability problems can be uncovered by three subjects, 80% can be found by five subjects, and as high as 95% of problems can be detected by nine. The task was to create layouts (TG) and collect interactions (DR) from four observational sets of data (two real and two video tasks).  The researcher (YZ) accompanied each user throughout the test to monitor his/her performance from the PC screen and log bugs/failures of system, confusing steps or errors in time, as users might miss reporting some bugs.  Further bugs and improvement ideas were identified through a post-test questionnaire.  System enhancements were carried out to develop the CLA system to the next generation.   METHOD The Usability Test was designed to be carried out in laboratory environment (Healthcare Ergonomics and Patient Safety research Unit (HEPSU) at Loughborough University).  12 people with various research backgrounds (e.g. Ergonomics, Computer Studies, etc.) were recruited as system users.  As they were novices, they were provided with CLA system manual, in order to familiarise themselves with the system before data collection.  During this practice period, users and their performance were monitored carefully by the researcher (YZ), to identify any bugs and breakdowns of system  and confusing steps and unclear   FIGURE 2  Assembly task one.    FIGURE 3  Assembly task two.    statements in user manual; these may take more time than expected to execute certain commands.  Two assembly tasks were chosen (figures 2 and 3) and video-recorded prior to the test.  Therefore, there were four tasks to be analysed using CLA system (two naturalistic data and two video data).  Randomisation was applied with the tasks analysed in different orders by different users.  Users were required to do their best to register every link, however, accuracy of results was not examined,   as it was assessed in the Technical Validation Test.  After the test, suggestions of improvements and bug experiences were obtained using questionnaires. RESULTS Suggestions of improvements and bug experiences were collected from monitoring the users’ performance as well as questionnaires, such as data buffer bug (the buffers were not emptied before a new data collection, this lead to results adding up).  All the improvements and bugs were analysed, system developments and improvements were carried out using this feedback. BETA TEST Beta-Testing of software systems or programmes is the last stage before release for public use.  The Beta-Test of CLA system aims to review its real-time data recording and analysis abilities and address further improvements. This is being conducted in a real environment – a hospital.  This test is being carried out at Emergency Department (ED) of Leicester Royal Infirmary (LRI), UK.  The physical movements of clinical staff at ED are shadowed by three system users (final year undergraduate students in Ergonomics, Loughborough University), with one student for doctors, one for nurses and one for healthcare assistants (HCAs)/housekeepers. METHOD Three system users follow the staff around the ED except inside patient cubicles when staff are talking or providing treatment to patient. They attempt to register every physical movement of the staff they are following using the CLA system.  Each system user needs to shadow 20 staff (3 x 20 = 60 staff), and observations are made for up to 2 hours for each staff member,  to collect enough movement data to produce valid link analysis results.  The system users will be interviewed after data collection at ED for software improvements.  Additionally, the link analysis results generated from the beta-test will be studied to review the layout and storage of equipment and consumables in the ED to increase efficiency and enhance performance. RESULTS Four pilot tests at the ED were carried out to obtained a detailed ED layout and familiarise the novice system users with the busy ED environment.  Although data are being collected using the CLA system, some ideas/improvements were fed back by system users, and developments are being conducted.   CONCLUSION This paper has described the CLA system and three iterative tests (technical, usability and field).  Technical Validation and Usability Test were satisfactory and the CLA system was proven to be accurate and reliable.  The Beta-Test is being carried out, it aims to review real-time data recording and analysis abilities of the CLA system.  Further improvements will be made to enhance functionality of CLA system. REFERENCES  Ferreira, J. &  Hignett, S. (2005), Reviewing ambulance design for clinical efficiency and paramedic safety. Applied E rgonomics, 36, 97-105. Glass Jr, J. T ., Zaloom, V ., &  Gates, D. (1991), Computer-aided link analysis (CAL A). Computers in Industry, 16(2), 179-187.  Hignett, S. &  L u, J. (2007), E valuation of Critical Care Space R equirements for T hree Frequent and High-R isk Tasks. Critical Care Nursing Clinics of North America, 19, 167-173. Jones, A ., Hignett, S. &  B enger, J. (2008), Identifying current and future care activities in ambulances, emergency departments and primary care. E mergency Medicine Journal, 25 (Suppl):A3 T horne, E . (2008), Development of a protocol to evaluate ambulance patient compartments using link analysis and simulation. Unpublished B Sc Report, Department of Human Sciences, L oughborough University, L oughborough, UK . T horstensson, M., Axelsson, M., Morin, M., &  Jenvald, J. (2001), Monitoring and analysis of command post communication in rescue operations. Safety Science, 39(1-2), 51-60.  V irzi, R . A . (1992), Refining the test phase of usability evaluation: How many subjects is enough? Human Factors:  T he Journal of the Human Factors and E rgonomics Society, 34(4), 457-468.  Whitehead, M. (2008), Task Analysis - An E rgonomic Assessment of an Office Photocopier. Unpublished Report, Department of Human Sciences, L oughborough University, L oughborough, UK . Zhao, Y ., Hignett, S., &  Mansfield, N.J. (2009), Computerised link analysis. Proceedings of the 2009 Naturalistic Decision Making L ondon, NDM9 ‘‘ NDM and Computers’’ , 390-398.  

Computerised link analysis

https://repository.lboro.ac.uk/articles/Computerised_link_analysis/9339104/files/16947764.pdf

Computerised link analysis

Abstract

Similar works

Full text

Available Versions

Crossref

Loughborough University Institutional Repository