Facilitating simultaneous engineering in the automotive industry via high speed networks, control passing and face-to-face video: Results from the car project

ELSEVIER International Journal of Industrial Ergonomics 16 (1995) 427-440

Industrial Ergonomics

Facilitating simultaneous engineering in the automotive industry via high speed networks, control passing and face-to-face video:

Results from the car project

Caroline Parker *, Sue Joyner HUSAT Research Institute, Loughborough, Leics. LE3 1RG, UK

Abstract

The European automotive industry requires frequent interaction and transfer of data between geographically dispersed designers and engineers at all stages of the product introduction process. The RACE CAR project identified and demonstrated Integrated Broadband Communications (IBC)-supported applications to support this process and improve competitiveness. User requirements for workstation-based, multi-media facilities including conferencing were identified. Two experiments were designed to investigate the role of face-to-face video and the means by which participants organise and control their interactions. These are critical issues in the multi-cultural, international environment of the European automotive industry. In the first experiment groups of three users solved a cooperative, screen-based, object manipulation task supported by different levels of communication. 'Linked computers plus an audio link' resulted in significantly faster completion times than either 'audio alone' or ' l inked computer plus audio and face-to-face video'. 'Linked computers plus audio' was also perceived as the most effective communications media. The passage of cursor via verbal agreement was successfully managed. Video was generally considered beneficial for initial introductions, assessing understanding and facilitating a stronger feeling of group identity.

In the second experiment, subjects were grouped under 'chaired' or 'free-for-all ' conditions and linked via (1) audio and linked computers or (2) audio, linked computers and face-to-face video. The task was similar to Experiment 1 and attempts to introduce contention were made through adding hidden, sub-goals. The task took significantly less time to complete in the 'video chaired' condition than the 'non-video chaired' or 'video free-for-all' conditions. This suggests that video has an important role in enabling a chairperson to control the meeting. Contention was not successfully achieved.

The results of the experiments suggest face-to-face video may be useful in chaired meetings and to develop ' team' feeling. A free-for-all method of control passing was seen as most appropriate although problems in achieving contention in Experiment 2 meant the impact of disagreement was not fully investigated. The results are discussed in relation to the European automotive industry and areas for further study identified.

Relevance to industry

The European automotive industry, which maintains distinct engineering functions in disparate countries, is striving to reduce the length of its design life cycle by improving communications between designers and engineers.

* Corresponding author. Phone: +44-1509-611088; Fax: +44-1509-234651; E-mail: [email protected]

0169-8141/95/$09.50 © 1995 Elsevier Science B.V. All rights reserved SSDI 0169-8141(95)00023-2

428 C. Parker, S. Joyner / International Journal of Industrial Ergonomics 16 (1995) 427-440

The studies described in this paper provide information of use to the developers and procurers of systems intended to support this process. In particular issues relating to the relevance of face-to-face video and use of control mechanisms for co-operative computer-mediated work.

Keywords: Automotive; Communication; Video; Conference control; Computer-mediated working

1. Introduction

The national, European a n d / o r global distri- bution of many manufacturing companies, cou- pled with the need to shorten product design lifecycles, has resulted in an increasing demand for the fast exchange of information. One barrier to this is the inability of current communications infrastructures to transport quickly, accurately and economically the vast amounts of data that pass between designers, suppliers, production engineers, etc. at all stages of the product introduction process.

In recognition of this problem, and in the belief that future economic performance will depend on effective, cheap communications and advanced infrastructures for information exchange, the European Commission set up the RACE programme to promote research into In- tegrated Broadband Communications (IBC). The work described in this paper was carried out within the CAR project ( C A D / C A M for the Automotive industry in RACE), involving a number of important automotive companies in Eu- rope. CAR, which ended in early 1993, concen- trated on identifying, developing and demonstrat- ing those IBC-supported applications and facilities which could support the product introduction process and improve the competitiveness of the widely distributed European automotive industry.

Early in the CAR project, the user requirements for IBC-supported workstation facilities within the automotive industry were determined (Powrie and Siemieniuch, 1990). These included the provision of multi-media messaging, a multi- user interactive sketchpad, high speed transfer of data, and workstation-based video conferencing. Although the companies already had video-conferencing suites (either private or public), workstation-based facilities emerged as an important requirement as the suites were heavily booked and not feasible for the day-to-day, problem-solv-

ing activities of designers and engineers. It was believed that easily accessible, workstation-based facilities would provide the point-to-point, multi- media conferencing necessary for informal meetings (characterised by talking, discussing, sketching out ideas, etc.) which are so important to team working (Allen, 1977; Kraut et al., 1990).

The user requirements survey (URS) described above provided the basis for specifying software applications and the range of top level functionality to be present in the CAR demonstrator. How- ever, as always, it was not possible to extract detailed requirements for all aspects of a system with which the user has no experience. For example, the user requirements analysis identified the need for some sort of interactive sketching tool but the exact method by which multi-user control of a sketching device, pen, etc., should be mediated was not provided. A number of specifically targeted experiments therefore took place to provide answers to issues such as these concerning the implementation of functionality. It was believed that failure to provide this information would result in software based more on the preferences of the software authors, rather than the needs of the users.

This paper describes two experiments which were designed to provide information on two major areas of interest to the CAR software designers: (1) The use of face-to-face video in remote con-

ferencing. (2) The means by which participants in a 'con-

ference' organise and control their interactions.

1.1. Face-to-face video

Face-to-face video was considered to be a useful facility by many of the end users interviewed at the beginning of the CAR project. Company management, however, felt that its use would add

C. Parker, S. Joyner / International Journal of lndustrial Ergonomics 16 (1995) 427-440 429

little or nothing to the efficiency or effectiveness of distributed working and would greatly increase its cost. There is some support for this latter viewpoint; Weeks and Chaperons (1976) investigated non-contentious problem solving and found no difference in task solution times between an audio and an audio/v ideo condition. A similar study by Gale (1991) found that video actually increased the time taken to reach a solution. Work by Kraut et al. (1994) suggests that videotelephony is used less by people working on documents as would frequently be the case in this industry.

A reduction in travel costs is often used to support a case for video conferencing (Harkness, 1986), particularly by video conferencing vendors, but as Gale points out, there is little empirical evidence to support these claims. In fact, the increase in collaboration engendered by the use of conferencing often leads to a greater demand for travel (Johansen, 1984; Johansen and Bullen, 1984).

On the positive side video has been reported as facilitating some of the social aspects of communication. For example, subjects use it when talking about what they observe, formulating hy- potheses, clarifying questions or suggesting strategies and checking for agreement (Smith et al., 1991). Certain types of video have been found to be useful for monitoring a partner 's direction of gaze; a facility which Isii et al. (1992) feel is very important in shared drawing activities. Pye and Williams (1977) suggest a video link is most useful for enhancing the social presence of group members which, in turn, increases their sense of team feeling. Indeed, positive correlations between subjective reports of 'social presence' and the bandwidth used have been found by Christie (1974), Christie (1975), Champness (1972) and Gale (1990), the highest scores being obtained when video is employed.

During the product introduction process the social functions of video may be seen as particularly important. As Harrison et al. (1989) point out: "Design is fundamentally a social activity. The purpose and effect of this social activity is to establish and maintain a shared understanding among the participants" (p. 86).

That video has something positive to offer in this process was demonstrated by Scrivener et al. (1993) in a long-distance study of design between the UK and Australia. The presence of video also seems to stimulate informal communication; Goodman and Abel (1987) observed an increase of 70% in the number of unplanned interactions between researchers based 1,000 miles apart. This was largely attributed to the presence of a video channel.

1.2. Conference control

The issue of conference control including turn-taking was the second key area of interest for human factors research within the CAR project and one where the results would impact directly on the software produced.

There are two types of conference control currently available to the users of a video conferencing suite; firstly, voice switching in which the 'floor' is passed to the person speaking at that moment and, secondly, chairing in which the 'floor' is allocated to an individual by the 'chair' of the meeting. These two types of control can be labelled free-for-all and 'managed'. This situation is further complicated in a workstation-based conferencing facility by the addition of the data channel (i.e. the means through which users share workstation-based applications). Its use means that software builders have to decide whether or not users should be given the facility to input data at any time (multi-user input) or have to take turns (single user input) and, if the latter, whether or not they require computer-based as- sistance to help them structure their control passing. The situation can be compared to a number of people contributing to a drawing on a single sheet of paper; should they be given a pencil each or should only one pencil be provided? If only one pencil is provided do the users need some form of guidance to ensure that each person gets a fair share of it or will existing verbal and non-verbal protocols as used in face-to-face meetings be sufficient?

The results of the URS suggested that two types of shared software needed to be accommo- dated within the CAR system: firstly, a purpose

430 C Parker, S. Joyner / International Journal of Industrial Ergonomics 16 (1995) 427-440

built interactive sketching tool which did not then exist as a commercial product and, secondly, a facility for engineers to share applications with which they were already familiar. In order to facilitate the free flow of ideas the sketching tool or 'sketchpad' was specifically designed to allow 'multi-user input'. The facility to share existing applications, however, could not be used in a 'multi-user input' mode as the existing applications were not designed to accommodate more than one input at a time. It is in this situation that users have to share the pencil and for which answers to the questions on control passing, as outlined in the previous paragraph, are required.

Experience suggests that, for the small groups most likely to make use of a workstation-based conferencing facility, the free-for-all method of interaction would be preferred. This is supported by a study by Austin et al. (1990) who found that a higher degree of satisfaction was obtained in groups using a free-for-all strategy. Development of this facility, however, places an additional burden on the software designers. It is relatively straightforward to structure the software so that the system mediates control passing, with users having to request control; facilitation of the free- for-all method is a more difficult problem. It is also possible that the free-for-all method could be counter-productive in situations of conflict where each person tries to maintain control of the communication device. Before clear guidance could be given to software developers, it was thus necessary to provide evidence that users could, or could not, manage free-for-all interactions without intervention, even in conditions of conflict.

1.3. Overview o f the experiments

Most studies concerned with the utility of face- to-face video and conference control have been based on video conferencing suites, as opposed to point-to-point conferencing. Consequently the results did not provide answers applicable to the type of workstation-based interworking envisaged by the CAR project. The experiments reported here were therefore intended to extend knowl- edge in this area and, in particular, to answer specific questions required by the designers and developers of the CAR software.

As outlined in the general introduction, the focus of this series of experiments was to explore two main areas: (1) The use of face-to-face video in distance

working. (2) The requirement for formal methods of con-

ference control. Much of the previous work into the use of

video or control passing has been grounded in the use of video conferencing suites (Sarin and Greif, 1985; Egido, 1990). More recent studies, while computer-based, have utilised tasks far removed from the graphical environment the automotive engineer of the future is likely to be using. The experiments were therefore created to simulate as closely as possible an automotive industry sce- nario, with designers and engineers working together on a CAD type problem.

The two experiments carried out are described in the following sections. The first focused on the use of communications media and the effectiveness of control passing for groups of three in a free-for-all environment (i.e. where no control is imposed by an elected 'chair' or by the system). The second experiment extended this work by investigating the same issues in a contentious task environment, comparing the results of chaired versus-free-for-all conditions.

2. Experiment 1 - Collaborative working and the use of video

2.1. Introduction

This experiment examines the effect on communication and task efficiency of three levels of communication: (a) audio linkage, (b) audio and computer linkage and (c) audio, computer and face-to-face video linkage, and to observe the means by which the groups managed their interactions.

2.2. Method

Nine male engineers with experience of com- puting, design or CAD were recruited from the general public as subjects. In a repeated mea-

C. Parker, S. Joyner / International Journal of Industrial Ergonomics 16 (1995) 427-440 431

sures design, groups of three were selected so that each subject completed each condition without working with the same person more than once. For technical reasons, employment of CAD proved impossible so a substitute task was developed which incorporated the requirements of being screen-based, employing the manipulation of graphics objects and requiring group interaction. This task required groups of subjects to build a computer-based 3D model from its pre-dawn parts using the Mac3D TM drawing package; parts had to be rotated by 45 ° or 90 ° and dragged into position. Group members did not meet beforehand and were seated at computer workstations in individual, sound-proofed rooms; each member had either the side, plan or end view of the final model (Fig. 1 shows an outline of the task).

Subjects w e r e individually briefed on the task and then linked via different communications media. The conditions investigated were: - Audio and non-linked computers (A); - Audio and linked computers (AC); - Audio, linked computers and face-to-face video

(ACV). In the audio condition (A) each subject built

the model on his own computer screen; the only

means of communication with the other two subjects was via a 'hands free ' headset. In the linked computer condition (AC), Timbuktu TM software was used to replicate one screen to the other two screens, thus allowing any subject to take control of the cursor or manipulate the model; changes were immediately replicated across all screens. This allowed all three participants to see the same screen image, but only one person at a time could use the mouse to manipulate the model. Groups were able to orient the shared image to match the paper cues they were provided with. In the video condition (AVC), a monitor was placed on each side of the computer and a camera positioned to obtain a good head and shoulders image. Each subject could thus see the other two team members; the layout is shown in Fig. 2.

2.3. Measures

Sessions were recorded on video for later analysis. The time taken for the group to complete the task was measured and, after each session, subjects completed 7-point rating scales to determine their attitude towards the communications media, ease of control passing, and sense of

H

Initial screen

/J "' "]D

End elevation

Fig. 1. An example of the parts of the model on starting the task and one view of the completed model (end elevation).

432 C. Parker, S. Joyner / International Journal of lndustrial Ergonomics 16 (1995) 427-440

Audio link Linked computer

Monitor 1 GZF itor 2

Fig. 2. Workstation layout for each subject for the ACV condition (subsets of the equipment shown were used in the other two conditions).

teamwork. They also completed questionnaires containing multiple-choice and open-ended questions to elicit subjective opinions on which medium was most and least effective; what they used the computer and video media for; how they decided who should take control next, and what they found most frustrating. Space was also provided for additional observations and comments.

2.4. Results

Table 1 summarises the mean times to task completion and mean scores for perceived effectiveness of the communications media; in the latter the maximum score was 35.

A Friedman analysis of variance found a significant difference for time to solution between conditions (p < 0.0001). A Wilcoxon matched-pairs

Table 1 Mean time to group solution and perceived effectiveness scores across subjects

A AC ACV

Mean time to solution (seconds) 3600 1661 2349 Mean perceived effectiveness from 22.8 32.0 29.8

rating scores (maximum 35)

signed-ranks test showed the time to solution in both the AC and ACV conditions to be significantly faster than the A condition (p < 0.004) where all groups had to be stopped after one hour (as shown in Fig. 3). AC was also significantly faster than ACV (p < 0.005) and was perceived by subjects as providing the most effective communications media (as shown in Fig. 4).

Mean time to solution (secs)

4000

3500

3000

2500

2000

1500

IOOC 0

o

O

8 o

: t I

A AC ACV Condition

Fig. 3. Mean time to group solution (seconds).

C. Parker, S. Joyner / hzternational Journal of lndustrial Ergonomics 16 (1995) 427-440 433

Effectiveness score (maximum 35)

40

30

20

10 0

[]

I I : A AC ACV

Condition

Fig. 4. Mean perceived effectiveness scores across subjects by condition.

Subjective ratings from the ACV condition showed face-to-face video to be considered the least effective medium for task completion, stat- ing it had little impact on the task and could be distracting. On the contrary subjects found linked computers a very useful task aid, enabling them to communicate and express ideas better. They also found the shared cursor useful for describing ideas and pointing.

Techniques for the passing of cursor control between subjects in the AC and ACV conditions were group-dependent but the cursor was generally given to the team member who had the best 'view' of the problem at a given time; this was agreed via the audio link. Subjects perceived this to be an adequate means of controlling interaction and only rarely was control of the cursor taken without prior agreement.

Although it was not possible to get empirical evidence that video contributed to group cohe- siveness for this short, task-oriented session, subjective responses suggest it may have had a social or team-building function. Subjects considered it beneficial for initial introductions, assessing the level of understanding within the group, and for catching the attention of others. They also felt it facilitated a stronger feeling of group identity.

2.5. Discussion

Within the context of the experiment, whilst linked computers proved a very effective commu-

nications medium, the addition of video increased time to solution. This supports the findings of Weeks and Chapanis (1976) and Gale (1990) that video does not improve, and may actually impair, task performance. However, subjective responses from the experiment support previous findings that video does have a social or team-building function. Although face-to-face video was not perceived as particularly important, all groups in the ACV condition used the cameras to display the plans they had been given. This supported the need for a rostrum camera or image transmission facility, as identified during the CAR URS. The difficulty experienced by those in the audio alone condition, where groups failed to complete the task, supports the common sense prediction that this type of visual task cannot be successfully carried out using audio communication alone.

No support was found for a formal chairing mechanism, either computer-mediated or human. Each team organised themselves to manage the task, with one member generally acting as a facili- tator and verbal protocols soon developing to ease the passing of control (e.g. 'why don't you do that?', 'shall I take control now?'. Positive responses to questionnaire items about the free- for-all method also support this view. It would seem that, for a co-operative task of this nature, normal social conventions of turn-taking and 'politeness' are adequate to manage the passing of control in a 'single input' (i.e. one pencil) system.

3. E x p e r i m e n t 2 - C o n t e n t i o n a n d t h e c o n t r o l a n d u s e o f v i d e o

3.1. Introduction

In all working situations there are likely to be elements of contention or competition. This may be particularly true of design: "The members of a design group typically represent various interests and in the course of their designing they confer with each other to reconcile their interests. In this sense designing can be understood as negoti- ation" (Harrison et al., 1989).


It is in these circumstances, where the parties involved in a conference have differing goals, that external control may be required to ensure that all parties have equal access to the system. Con- tentious situations may also result in a greater need for visual feedback from the other partici- pating parties, evidence for which is suggested by Abel (1990). As one of his users commented " to me it seems there is something indispensable about face-to-face contact in those situations where you want someone to disconnect from their position on a solution just long enough to really get in touch with your view or position".

The next stage in the investigations was therefore to test the findings of the first experiment during completion of a contentious interactive task. Contention in this context was intended to approximate a situation where several people come together to complete a task, each having their own sub-goals to achieve. For example, the component engineer may be trying to redesign an assembly to solve an engineering problem, the component engineer of an adjacent part may be unwilling to make changes to his area of the vehicle to accommodate this, and the purchasing department may want to use the same assembly as other variants to reduce volume costs. Each will be trying to achieve their own sub-goals while contributing to the solution of the problem at hand.

Given the results of Experiment 1 it was not deemed necessary to repeat the audio only (A) condition. In addition to the video and non-video conditions a new variable was added to investigate control issues more fully with subjects grouped under chaired or free-for-all conditions.

3.2. Method

Thirty-six subjects with experience of comput- ing, design or CAD were recruited from the general public and student populations. A replicated measures design was employed, with subjects semi-randomly formed into groups of three (the male / female split within each condition was controlled). The task was the same as that used in Experiment 1 (see Fig. 1). Group members did not meet beforehand and were seated at com-

puter workstations in individual, sound-proofed rooms. They were then briefed individually on the task before linking them via the communications media to be used during that condition. Each subject completed one session only and the conditions investigated were: - F a c e - t o - f a c e video, 'free-for-all' method of

passing control (V/FFA) ; - No face-to-face video, 'free-for-all' method of

passing control (NV/FFA) ; - Face-to-face video, 'chaired' method of passing

control (V/Ch) ; - N o face-to-face video, 'chaired' method of

passing control (NV/Ch) . In the chaired condition one member of the

group was given the task of chairing the group during its completion of the task. They were told to ensure that each person took their turn as directed but no further instructions as to how this should be achieved were given. To encourage contention each of the three group members were given a different and conflicting sub-goal which they had to achieve in addition to the group task of building the model. These sub-goals are shown below: - To complete the task as quickly as possible. - To complete the task in as few moves as possi-

ble. - To complete the task as accurately as possible.

These sub-goals had proved extremely effective in creating contention during an earlier pilot study. As an incentive a small cash payment was promised to each subject if their group achieved the desired sub-goal (i.e. completed the task fastest, in the least moves or produced the most accurate solution). Group members were made aware of the identity of the chairperson prior to starting the task but the presence of sub-goals for each person was not disclosed to the group as a whole. The sub-goal to be performed was made clear to each person individually and they were led to believe that theirs was the only 'hidden agenda'.

As in the previous experiment Timbuktu T M

software was used to link the computers. In the video conditions ( V / F F A and V/Ch) , two moni- tors were placed on the right hand side of the computer and a camera positioned to obtain a

C. Parker, S. Joyner / International Journal of Industrial Ergonomics 16 (1995) 427-440 435

Mean time to solution (secs)

4000.

3500

3000

2500

2000

1500

1000 0

V/FFA NV/FFA V/Ch NV/Ch Condition

Fig. 5. The mean time to solution for the four conditions.

good head and shoulders image. Each subject received an image of the other two team members.

3.3. Measures

Sessions were recorded on video for later analysis. The time taken for the group to complete the task was measured and, after each session, subjects completed 7-point rating scales to determine their attitude towards the linked computers, face-to-face video, ease of control passing, and sense of teamwork. They also completed questionnaires containing multiple-choice and open- ended questions to elicit subjective opinions on which media was the most and least effective; what they used the computer and video media for; how they decided who should take control next; and what they found most frustating. Space was also provided for additional observations and comments.

3.4. Results

Results were analysed using non-parametric methods. There was no overall difference between conditions on time to solution although there was a significant difference between the N V / C h and V / C h conditions and between the N V / C h and V / F F A conditions. Mann-Whitney

tests showed the V / C h condition took significantly less time to complete than the N V / C h and V / F F A conditions (for both z = - 1.993, p < 0.05) (see Fig. 5).

No overall differences between chaired and non-chaired, or between video and non-video, were found for any of the statement categories. There was, however, a significant difference between conditions on the questions which assessed the level of team feeling (see Fig. 6). Here the non-video chaired condition produced significantly lower scores than all other conditions which scored approximately the same.

Although subjects were randomly assigned to conditions, a post hoc Mann-Whitney analysis of the subjects' biographical data was conducted. This revealed a significant difference between the chaired and free-for-all conditions on experience with Macintosh computers (z = -2 .17, p = 0.02). The free-for-all conditions had a greater level of Macintosh experience than the chaired conditions. This may have resulted in an artificially low time to completion in the non-chaired conditions. No effect of any other biographical variable (e.g. age) on the conditions was found.

Observation of the subjects during the experiment and analysis of their subjective responses afterwards indicated that contention between participants was not successfully achieved.

Mean team feeling score (maximum 7)

7.0"

6.5"

6.0'

5.5"

5.0.

4.5.

4.0"

3.5'

3.0, 0 ! I I I

V/FFA NV/FFA V/Ch NV/Ch Condition

Fig. 6. Mean scores for 'team feeling' statements.


3.5. Discussion

The results of this experiment indicate an in- terdependence of video and control issues. The introduction of the control conditions 'free-for-all' and 'chaired' produced a situation where the use of video reduced time to solution in direct contra- diction to the findings of Experiment 1 and to the findings of Gale (1990) and Weeks and Chapanis (1976). However, the introduction of a chairperson to the task appears to increase the time it takes a group to reach a solution unless that group also has the use of face-to-face video. This suggests that video enables the chairperson to control the meeting and that without video there is insufficient means to do this. It also suggests that a chairperson supported by video is a useful institution in this type of task situation. The use of a chairperson without video, however, is not productive and appears to reduce the feeling of team spirit reported by subjects.

Why should this be the case? The role of team chair, and its responsibility for directing the actions of others towards task completion, places an additional burden on the person involved. It requires them to be continually aware of what the other members of the team are doing; understand and choose between alternative solutions presented to them; ensure that team members re- ceive and obey instructions; and resolve conflicts. Based on the results above it could be hypothe- sised that these responsibilities require information over and above that provided by a simple audio link and beyond that required for non- chaired interaction. This additional information is perhaps summarised by Argyle (1969), who states that visual communication: - Provides evidence that each person is attend-

ing to the others; - Co-ordinates patterns of speaking by means of

head nods; - Provides feedback.

Support for this view is found in Gale's (1990) paper where he states that the video channel was seen as particularly effective in assessing the attention of the other members of the group.

This experiment, however, failed to replicate the conditions of contention produced in its pilot

study. While the sub-goals used in the pilot study were successful in producing the desired be- haviour, those same sub-goals appeared to be ignored or only periodically adhered to during the experiment. Subjects remained polite and co- operative throughout. The only variable which was not held constant between the two conditions, and which was likely to be the cause of the failure, was that of the subjects' familiarity with one another. Subjects in the pilot were more familiar with one another than those in the experimental study and this appeared to lead to a greater willingness to argue and compete.

4. G e n e r a l d i s c u s s i o n

4.1. The role of video

The main focus of the CAR project was to specify, design and demonstrate a system to en- hance and facilitate the exchange of information and ideas between geographically dispersed members of an engineering team. The evidence to date has offered little to contradict the view of automotive management that face-to-face video is an 'add-on', rather than an essential part of this system. Indeed, the results of the first study suggested that video, rather than enhancing task performance actually degraded it, significantly increasing time to solution. Subjective responses also indicated that the video was perceived to be a distraction to the computer-based task at hand. These negative findings may be due to the re- stricted interactions permitted by a video link (Gaver, 1992). However, the results of the second experiment lead to the conclusion that the combi- nation of face-to-face video and a group leader or 'chair' could significantly reduce time to solution, thereby improving productivity.

It should be noted here that the assessment of 'quality of solution' is another issue and one which we felt unable to measure with any degree of accuracy in this type of task. However, there is some evidence in the literature to suggest that the presence of video leads to greater considera- tion of the implications of a problem. For example, Smith et al. (1991) reported that the addition


of a video channel in their 'shared ark' experiment encouraged interactions about the problem as opposed to those specific to the operation of the interface (i.e. meta-level rather than task-level interactions).

The possible social function of face-to-face video has been identified by a number of studies in this area. Results of these studies are usually based on subjective data relating to feelings of ' team spirit' or how well subjects felt they knew the other participants and this is supported by the questionnaire results of Experiment 1. These observations are very difficult to measure objec- tively and can only really be tested over a long period of on-site use. For example, Abel (1990) found that a group of geographically disparate lab workers who made regular use of face-to-face video felt they knew each other well enough not to have to engage in 'extensive social protocol'.

Based on the evidence above, a case for the incorporating facilities for face-to-face video into the CAR system could be made. There is insufficient evidence to suggest that video should be made available for each transaction as the cost remains high, even if the low quality images produced by ISDN transmission are used. However, it could be argued that the additional cost of providing a 'video facility' (e.g. plug in unit, lim- ited use software or specialised workstation) would be covered by: - The increase in productivity in situations where

a meetings 'chair' can be used (e.g. team meeting led by a manager).

- The development of ' team' feeling in groups who might not otherwise meet regularly.

- A potential improvement in the quality of deci- sions made. The second point will be key in the develop-

ment of multi-disciplinary teams required to re- alise the concept of simultaneous engineering.

However, the real benefits of face-to-face video to the automotive industry are difficult to assess within short experimental sessions and it is felt that its full role within the context of the CAR project could only be truly defined by putting the technology in the user companies for an extended trial. This view is supported by Tang and Issacs (1993), who suggests the value of video is more

likely to be observed in this case as its use has an effect on work processes, rather than the results of work.

4.2. Conference control

While the results of Experiment 1 lead to the opinion that a free-for-all mode of working would be preferred by users in the automotive industry, Experiment 2 results suggest that it may be more productive to use a chaired method where video is provided. This supports the conclusions of Austin et al. (1990) who found that a chaired interactive improved the quality of the task un- dertaken. In the absence of video, however, the use of a 'chair' in a group interaction would appear to be counter-productive. In both the chaired interactions and the free-for-all ones users quickly developed a variety of verbal protocols for passing, requesting and taking control in an or- derly fashion. To offer flexibility depending on the type of meeting to be held, it may be necessary to include a number of mediated methods of floor control which users can select prior to the commencement of a meeting, as in the MER- MAID system (Watabi et al., 1990). However, a free-for-all default is suggested. In the context of design this view is supported by the work of Bly and Minneman (1990), who maintain that one of the four requirements of a shared drawing space is the ability to 'mark, write and gesture in the same space simultaneously'.

4.3. The scope of multi-media conferencing

It is not suggested that multi-media conferencing will replace face-to-face meetings in the automotive industry but it could provide an additional, effective, informal means of interaction between teams of users. Egido (1990) stressed the view that video conferencing is not a substitute for face-to-face meetings but could prove useful to a business 'provided suitable applications have been clearly identified'.

5. Conclusions and future work

As video will not generally be available, the advice given to the software developers on the


basis of the results so far was to produce systems that operated on a free-for-all basis. There seemed to be no social reasons for the development of computer-based mechanisms of floor control, with users having proved themselves more than capable of controlling an interaction without it. However, the impact of disagreement between participants during computer mediated meetings has not yet been fully explored and an additional trial is needed to determine the requirement for controlling a conference under these circumstances.

Further trials could also explore the utility of the video channel in circumstances likely to be encountered by the participants in the product introduction process. For example, the cross cultural nature of the design process in European automotive manufacturing suggests it may be appropriate to investigate empirically the use of video in mixed language groups. Given the extra burden of communication when participants in a meeting do not share the same first language, it is possible that face-to-face video will be of greater importance than has been suggested by the re- suits here.

The earlier work of the CAR project suggested that users had a need to be able to show remote colleagues an object, document or drawing which was not currently represented on the computer system. For example, a test engineer may want to show the worn parts of an engine piece that failed under test. While this is a simple matter when all are gathered around the same table, the exact requirements for examining the object re- motely are not known. A future experiment might explore the requirement for remote control of the camera (with its attendant problems in a group situation) versus local control, where the owner of the pa r t /document etc. responds to group requests for movement and magnification. The requirement for image quality under these circumstances is also likely to be greater than for face-to-face video. Given the high cost of bandwidth, it is likely that users in the automotive industry would also be interested in the results of any experiment which explored the relationship between image quality and its usefulness for this type of task. The identification of the cut-off

point where the quality of the video image is no longer suitable for viewing objects would be particularly useful.

The prototype multimedia system developed within the CAR project was evaluated by multi- disciplinary teams from each of the three user companies during the last six months of the project. This evaluation took place across three sites in the UK and France and real engineering tasks using data supplied by the companies were used. Issues of relevance to this paper investigated during the final CAR trials were: - To determine how well users felt the CAR

system would encourage and support Simulta- neous Engineering and to identify which tasks would particularly benefit (e.g. technical deci- sion-making versus project management).

- The current and future organisational implications for users and user companies (jobs, roles, responsibilities, etc.).

- Users' perception of ' free for all' applications versus those where the user had to request floor control (both types were present in the demonstrator).

- Use of video and audio. Data was obtained via subjective question-

naires, with concurrent monitoring and post hoc v ideo/audio analysis providing additional information. A full description of the trial and results is presented in Joyner (1992); the main findings of relevance to this paper are discussed in the following paragraphs.

Most users felt that a system like CAR would help create a Simultaneous Engineering environment although some interesting points were raised(e.g, that, although facilitating Simultane- ous Engineering, a CAR system would not re- move the psychological ' them and us' attitude that tends to exist where individuals are spread across different geographical locations; and another stated that the system would not create lines of communication that did not already exist). Only one user implied that this type of system would not be a prime driver towards a Simultane- ous Engineering environment - in his opinion it would be more beneficial to co-locate personnel on one site to improve communication links rather than via an advanced IT system.


Although users liked both ' free for all' and 'f loor control ' methods of interaction, a significant majority preferred ' f ree for all' which was recommended as being the single most appropriate means of interaction for three-way working. However, there is a case for providing both modes of interaction as a user-selectable option, thereby offering the flexibility required for different applications, group sizes and working situations. Having both methods present could cause confu- sion but this was not really tested during the trials.

The importance of a high quality audio link was clearly demonstrated. Some form of hands- free audio is definitely needed although the exact requirement for the type of audio link (i.e. hands-free or headsets) will depend on the environment in which the system is being used and the preferences of the users. As the experiments carried out within the project suggested, the users did not rate video as a major communication requirement. However, users in the trial did feel that being able to see the other person was extremely helpful in providing feedback on their actions and in easing the social contact between individuals who may or may not know each other. The video was also perceived as useful for show- ing the other user(s) components.

Many of the issues discussed during this paper are of relevance to a R A C E II project, SMAC (Suppliers and Manufacturers ' in Automotive Collaboration) which is developing a demonstrator to enable suppliers and manufacturers on remote sites to work together at all stages of the product introduction process. Like CAR, SMAC is set within the European automotive industry and is continuing to investigate the industry's precise requi rements for workstat ion-based, multi-media conferencing between multi-disciplinary teams of manufacturers and its first tier suppliers. The potential benefits to be gained from applications supported by high speed communications links are enormous. A car manufacturer may have a supplier base of 500 first tier suppliers and 8,000 second tier suppliers, all of whom play an increasingly important role in the design, development and manufacture of the fin- ished car. These supply chains have evolved over

many years, leading in many cases to more open- ness between suppliers and manufacturers; in some cases with strategic 'open book' partner- ships across the whole supply chain. However, it has not been possible to exploit fully the benefits of these new relationships, mainly because of technological constraints and the lack of information and communication infrastructures to support discussion and the exchange of ideas and data between geographically dispersed teams. For example, a leading car manufacturer has esti- mated that time to market could be reduced by up to 40% by incorporating enabling technologies such as high speed communication links and distributed interactive, multimedia systems into their design environments. Early results from the demonstrat ion of the first SMAC prototype systems in this supply chain context suggest that the user requirements in terms of video and control of conferencing are very similar to those of the CAR project. This provides a measure of corrob- oration for the findings of the CAR project, espe- cially since the automotive industry collaborators in the SMAC project were different to those in CAR. This indicates that the issues covered within this paper can be applied across the automotive industry and its supply base; they will be investigated further during the on-going development and evaluation of the SMAC software.

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Facilitating simultaneous engineering in the automotive industry via high speed networks, control passing and face-to-face video: Results from the car project