Using videos to improve operations | Part 7 – Detailed review of process segments

Asenta 2011-03 Roberto Cortés

Roberto Cortés

Asenta Juan Ortega head shot

Juan Ortega

This post was co-written with Asenta’s Roberto Cortés and Juan Ortega, based on a joint project in Spain in October, 2013. A detailed analysis of the video recordings on two operations was key to generating improvement ideas that the plant has implemented since. The company had shot some videos of operations before, but not used them this way before, and it was a learn-by-doing experience for the participants. 

The demand for the company’s products is growing, and it is struggling to keep up. Its core technology is a fabrication process, and engineering has focused its attention on it to increase capacity. After fabrication, however, the product needs several assembly operations. From direct observation, it was clear that the operators were working at a pace that could not be sustained for a whole shift. The manager confirmed that the pace slackened and the quality dropped towards the end of the shift.

The challenge was therefore to change the assembly process so that the operator could complete the tasks within the takt time of about 60 seconds, at a steady, sustainable pace, without running ragged or getting exhausted. While on site, we focused on two operations, shot videos as recommended in earlier posts — from an elevated position and focusing on the operator’s hands — and coached the plant team on reviewing the videos, with the goal of enabling them to do it on their own for the other operations.

Preparation

The detailed review breaks the operation down into its smallest identifiable steps  to discover improvement opportunities for each. If you are going to do this on a regular basis, you should probably invest in software to collect timestamps from videos, categorize the steps, and record improvement ideas, like Timer Pro or Dartfish.  Timer Pro was developed specifically for Manufacturing; Dartfish, for sports, but it has also been used in Manufacturing.

For the first time, it is best to do it on short operations, and you can make do with an Excel spreadsheet on which you manually record the timestamps. It needs the following columns:

  • Step number
  • End time
  • Step duration, calculated from the timestamps.
  • Cumulative time, aggregated from step durations.
  • Operation Description
  • Operation Category
  • Improvement Ideas

Sufficient time has to be allowed for the detailed review. It is customary to allow between 3 and 5 times the length of the recording and even more if the recording is very short. It is recommended to have a sample of the product and components at hand where the review is being held.

Asenta----Product-sample-in-conference-room

Product sample in conference room

Review

The video is analysed and the spreadsheet completed step by step. For short steps, you can play the video in slow motion  to give time to observe details. Because you are going to be adding times, you need record the timestamps at a higher precision than you are really interested in. For example, to analyze time in second, you need to record the timestamps to one tenth of a second. The video and the form are shown on the screen at the same time.

Asenta----Video-and-analysis-form-on-same-screen

Video and analysis form on the same screen

While conducting the analysis, do the following:

  • Describe each step with an action verb and a single object. If you find you can’t, break it down further until you can.
  • Do not criticize ideas. Write them down for later evaluation.
  • Aim to eliminate unnecessary steps (muda), reduce the variability in how the steps are carried out (mura) and their inconvenience (muri).
  • Assign a category to each step so that you can aggregate times by category.

You can generate your own categories as you go along and standardize them as you reach conclusions. There must not be too many (5 better than 10) and they are usually of the following type:

  • Pick up/put down
  • Walk
  • Assemble
  • Inspect or test
  • Wait
  • Adjust
  • Rework
  • ….

If there are large differences in how different operators perform the operation, several videos can be screened at the same time, with the same task carried out by different operators. It is essential to carry out this detailed review with the operators in the videos. They know things that nobody else knows, and have ideas that you want to use.

Asenta -- Operators participating in analysis

Operators participating in the analysis of their own work

Conclusions

When you analyze operations for the first time, it is common to discover that about 40% of the time is spent on activities other than assembly or test. This is due to a combination of wrong sequencing, redundant steps, multiple handling, inadequate fixtures, inconveniently located tools or parts, etc.

Of course, not all of these can be eliminated easily. Some can be, by redesigning or retrofitting the work station; others can be taken out of the assembly flow and performed in parallel so that, for example, the operator does not have to prepare a part while the product waits. The net productivity increase that can usually be accomplished is on the order of 30%, without overburdening the operator. In our client’s case, this means making the assembly jobs sustainable while absorbing a higher demand.

Once the summary of times by category has shown the “gold in the mine” — that is, the improvement potential, the team fleshes out the ideas generated during the review of the video, tries them out as much as possible immediately, and turns them into proposals. The following pictures shows the flip chart with sketches of the proposals generated in our sessions, and a snapshot of try-storming.

The team then turns the  improvement proposals into a detailed action plan for the short, medium-, and long term.

Once the improvements are implemented, the team shoots another video of the operation, for the following purposes:

  • Validating the improvements.
  • Standardizing the sequence of operations
  • Training other operators

Using videos to improve operations | Part 4 – Watching as a team

Starting with dissecting the video second by second is a recipe for getting bogged down and never finishing. The point of analysis at the gesture level is to answer quantitative questions about the operation’s improvement potential but, at the outset, we don’t even know what questions to ask. A video is a rich data source; we can zoom in anywhere in it, but first we need to identify where it is worth doing by viewing it end-to-end as a team, breaking it down into major phases, and stopping along the way to collect explanations, comments and ideas.

In a video of an assembly operation involving a machine, the phases might be:

  1. Place components on fixture.
  2.  Unload previous unit from the machine.
  3. Load fixture with new unit on the machine.
  4. Start the machine cycle.

If the video shows museum attendants setting up barriers of stanchions and belts to channel the flow of visitors, the phases might be:

  1. Bring carts of stanchions from storage to the reception area.
  2. Erect the barriers.
  3. Return empty carts to storage.

This first viewing of the video is an opportunity for the operators to see their work as a third-party would, which differs from the way they perceive it as they do it. The other participants in the review not only learn how the process is actually done, and to discover steps that are not in the specs.

One operator adds a cleaning step to the job of attaching stickers. When asked about it, she readily admits that she does it to fill up her time: her station has been assigned less work than the upstream and downstream stations, and she is embarrassed at having to wait. That comment identifies this assembly line as a target for rebalancing, and for the detailed analysis that supports it.

Another operator, as a fender subassembly station, is recorded walking to the front of the fender, running his hand over the surface and looking at it intently. This is not in the spec either, and he explains that he has noticed scratches, that he thought were generated when the front of the fender rubbed against the floor of the carrier in which it came from the paint shop. This is a quality problem no one else is aware of, and foam strips are promptly added to the carrier floors to keep it from recurring.

This viewing is also an opportunity to comment about sharp edges, heavy parts, missing tools, slippery surfaces, obsolete instructions, poorly located resources, etc.,  and to brainstorm on remedies. The observation that the operator below appears to spend half her time reaching for parts in distant bins leads a discussion of possible means of providing these parts closer to the fixture.

Automatic riveting station

In the next example, three museum employees move a cart of 16 stanchions from storage to deployment: one to push , one to steer and one to open doors in front of it and close them after it. The explanations are as follows:

  1. The cart is tall and the pusher can barely see over the top.
  2. The four wheels swivel freely, which makes the cart difficult to steer.
  3. Without a door-person to clear the way, the cart would have to stop and go multiple times.

Concourse setup Cinepak

Figure 2. Cart with stanchions at museum

 During the erection of the barriers in Figure 3, the team makes the following comments:

  1. The stanchions are held horizontally in the cart but used vertically, which requires extra handling of these 30-lb parts.
  2. Rather than moving carts around to where stanchions are dropped, the carts stay in one location, and the employees carry or roll them to their destinations.
  3. Pulling the belts between stanchions is done separately from setting them down.
  4. Some stanchions are not located properly and rework is necessary.

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Figure 3. Erecting the barriers

 The ensuing brainstorm comes up with the idea of using smaller carts handled by just one person, with fixed rear wheels, each carrying the stanchions needed for one barrier, held vertically, and with the belts pre-connected. One door opener/closer suffices for the entire group. Each employee then erects his or her barrier by simply dropping the stanchions in sequence at the assigned locations, of which a map is mounted on the cart.

At the end of this process, we have many ideas, some of which can quantify by drilling into the details of relevant sections of the video. It may be hard to quantify safety or quality improvements, but we can measure how much time is being spent on tasks we propose to eliminate. We now have questions that a targeted detailed analysis can answer.

The frequency with which this work is done also plays a major part. The assembly work in Figure 1 is done every 17 seconds; setting up and taking down the stanchion barriers in front of the museum is done once a day. The stakes in improving both are obviously different. In the first case, it is using one operator instead of two, and having fewer quality problems at the end of the shift due to operator fatigue.

What about the museum? What does it gain if the barriers are erected in three minutes instead of nine?

The employees who do this work are from Guest Services, which means that they sell and process tickets at the gate, give maps to visitors, direct them to exhibits, restrooms, the store or the restaurant, and reunite stray children with their parents or teachers. They are the face of the museum to the visitors who represent the bulk of its revenue. The Guest Services employees contribute most to the visitors’ experience through direct contact, and there is therefore value in reducing the amount of time that they spend on tasks like setting up barriers, which do not involve such contacts.  If this were the only such task, improving it would make little difference, but they are involved in other, similar tasks throughout the day, to which similar ideas apply.

When brainstorming, you want to keep all the ideas already expressed in full view of all participants, to stimulate further idea generation. For future use, you want to record these ideas electronically, and linked to the corresponding video scenes. The first objective is met by flip charts on the walls all around the room; the second, by attaching comments to video segments using annotation software. If you use only flip charts, then someone will have to transcribe their content after the fact, which will add a delay and introduce errors. It is done faster and better during the meeting by having a dedicated scribe who is proficient in the use of the annotation software.

Unlike stopwatch time studies or motion studies based on predetermined time standards, videos not only allow us to do a coarse analysis of some sections and a fine analysis of others, but also to change our minds and go back to a segment we skipped over and examine it in detail.

Using videos to improve operations | Part 3 – Shooting shop floor videos

Following are a few recommendations on the art of taking shop floor videos:

  1. Special requirements on shop floor videos. We have already seen that the requirements for shop floor videos differ from those of other uses of this technology. If you shoot a family or sports event, you will naturally want the highest resolution you can get, which would be counterproductive here. Likewise, shooting a video for the purpose of data collection is different from doing it for art or entertainment.For example, the Youtube video of a NASCAR pit stop looks somewhat like a shop floor video but isn’t one. It is entertaining and dramatically shot, but not usable for analysis. In fact, a shop floor video that captures everything that is needed for analysis is likely to bore anyone who is not directly involved with the target process.

    This needs to be considered when deciding who will be holding the camera. You will naturally prefer someone who is already handy with it, and that is likely to be from experience capturing family occasions, sports, or from making movies as an amateur. The ability to keep a camera steady and pay attention to lighting, composition and focus is valuable, but the camera operator will have to be coached on the specific objectives of shop floor videos.

  2. Applications to setup time reduction or to the improvement of a work station. the camera needs to be looking down at the operator’s hands. In short operations, it can be done by holding the camera with a raised arm, and using the swiveling LCD screen for control. This gets tiring quickly and requires standing in such close proximity to the operator as to possibly interfere with his or her movements.
    Many plants have mezzanines or catwalks that provide a view from above. Being observed from such a place, however, may be uncomfortable for the operators, as well as too far to zoom in on the hands and capture any voice comments. The middle ground is to shoot from the top of a stepladder located within zooming and hearing range of the operator station, just far enough to avoid any kind of interference

    Amin recording operation

    Shooting a video from a stepladder.

    This works, until the operator leaves the station to walk beyond the reach of the zoom, at which point getting down off the stepladder to follow the operator while recording causes a few seconds of the action to be lots. A better solution is to hand over the camera to another team member on the ground, or even to involve more than one camera. In any case, this needs to be planned. Image stability is not an issue on the stepladder, but it is when following an operator’s movement across the floor, and you do not want a video that will make participants sea-sick during review. While professional tracking shots require equipment that is not available in a factory, some amateurs have supplemented the camera’s own image stabilization by shooting from a wheelchair.

  3. Fixed position on a tripod for time-lapse videos. Setting the camera on a tripod in a fixed position is not appropriate for this kind of analysis, but is when taking time-lapse videos of a large area for purposes of work sampling.
  4. Recording the position and orientation of the camera. It is also necessary to record on a layout of the shop floor the position and orientation from which the video is shot. The point is to return to the same location to shoot another video to document the improvements once implemented.
  5. Number of repetitions. Traditional time studies involve taking measurements on the same operation 6 to 10 times, for the purpose of improving precision when setting standards of operator performance. But our purpose in recording operations is not to set standards but to change processes to make the work simultaneously easier, safer, less error-prone, and faster.
    All we need for this purpose is one representative execution, and the operator can tell us if there is anything special or abnormal about it. If possible, we just take it into account during the analysis; otherwise, we make another recording. To make sure we have one complete execution, we start recording a few seconds before the operation starts and stop a few seconds after it ends.
  6. Scale. The presence of people in the videos gives us at least a rough sense of scale, but sometimes we would like more precision, for example to know how far an operator has to reach for a part, or how fast a cart is rolling. The following shots show the extreme measures the Gilbreths took for this purpose, with a gridded background. The picture also shows a large and precise timer, which was necessary because they used imprecise hand-cranked cameras.
  7. No editing. We do not edit the shop floor video, except possibly to add a title and administrative data at the beginning, Otherwise, we use it in the analysis exactly as shot. It is raw data, and we want to keep it that way.

Using videos to improve operations | Part 2 – Management Preparation

Whether on the shop floor or elsewhere, starring in a video makes people nervous, particularly when they don’t know how it will be used and when it is done by strangers. On the shop floor, particularly when unions are present, operators fear that the videos recordings will simply be used against them and to  justify layoffs. Unless these fears are put to rest before the shoot, it will be tense and, if it happens at all, the quality of the data will be affected.

Following are key steps to follow:

    1. Have a clear objective. Videos can be used for many purposes:
      • Setup time reduction. This is the most common current use in Lean implementation.
      • Work Sampling. A time-lapse video of a work area can be used as a series of snapshots on which to count the people and machines by category of activity, providing rough estimates of proportions of time spent walking, waiting, carrying parts, processing work pieces, etc.
      • Analysis of team coordination. You record from a distance the movements and state changes of multiple people and machines. You don’t see the details of what each one does, but you identify situations where they:
        • Walk long distances, empty-handed or carrying heavy parts,
        • Cause others to wait,
        • Deadlock each other,
        • Fix the work done by others,
      • Details of work done at an individual station. You focus on the hands of one operator through a sequence of steps at a work station, with the goal improving both individual steps and their sequencing.

      This is necessary not only to plan the shoot so that the video supports the objective, but also to identify the people who will be recorded and the ways in which the analysis may affect them.

    2. Secure the consent of the participants. The people recorded in the video are not the object of a project but participants in it. It should only be done if they and their management agree. This entails the following:
      • Review the project with the direct supervisor of the area first, and proceed only if he or she supports it. The supervisor needs to agree to let operators participate in video analysis sessions, during work hours if they can be temporarily replaced in production, and in overtime otherwise.
      • If the plant is unionized, review the project with the union leadership. Unless prevented from doing so be constraints external to the plant, unions support the project once they are reassured that:
        • The purpose is not to make people work harder.
        • It is no threat to job security.
        • It usually improves safety.
      • Review the project with the operators, in the presence of their supervisor and a union representative if applicable.
      • There must be a clear policy on the handling and dissemination of videos after the analysis. The principle to follow is that what happens on the shop floor stays on the shop floor. The videos are not to be shared with any outsider to the project. VHS cassettes were easy to safeguard; MPEG files on hard disks are a different challenge. They need to be organized in a video database with proper indexing and safeguards, which is a whole other subject.

Using videos to improve operations | Part 1 – Overview and Motivation

This is the first in a series of posts about  the use of video technology to improve operations. This technology is now so pervasive that it is nearly impossible to buy a phone that does not include a camera capable or recording footage that is good enough for broadcast news. Journalists use amateur videos to show storm damage or expose human brutality. We use it to identify improvement opportunities in operations.

For long-time followers of this blog, this is closely based on comments I posted 18 months ago about a news article on the application of a sports video analysis package to manufacturing. The forthcoming installments, on the other hand, are completely new. 

Contents:

Frank and Lillian Gilbreth did it 100 years ago

Motion pictures have a long history in manufacturing. In 1895, the first film ever publicly projected onto a screen showed women leaving the Lumière Brothers factory in Lyon. In 1904, the American Mutoscope and Biograph Company shot several scenes in Westinghouse factories. In 1913, Frank and Lillian Gilbreth were probably the first to use this new technology to analyze operations, and a compilation of their films is available on line, which shows that, from the very beginning, the camera was much more than a substitute for the stopwatches used by Taylor. As is obvious from watching the Gilbreth films, where Taylor measured in order to control, the Gilbreths observed in order to improve. Taylor’s greater fame or notoriety, however, obscured this fundamental difference in the public mind, and made workers as wary of cameras as of stopwatches.

According to psychologist Arlie Belliveau:

The Gilbreths used workers’ interest in film to their advantage, and encouraged employees to participate in the production and study of work through film. Participants could learn to use the equipment, star in a film, and evaluate any resulting changes to work practices by viewing the projected films in the labs or at foremen’s meetings. Time measurements were made public, and decisions regarding best methods were negotiated. By engaging the workers as participants, the Gilbreths overcame some of the doubt that followed Taylor’s time studies.”

In other words, these pioneers already understood that, unlike the stopwatch, this technology enabled the operators to participate in the analysis and improvement of their own operations.

Until recently, however, the process of recording motion was too cumbersome and expensive, and required too much skill, to be massively practiced either in manufacturing or in other types of business operations. In addition, most managements failed to use it in as enlightened a way as the Gilbreths, and manufacturing workers had a frequently well-founded fear that recordings would be used against them. As a consequence, they were less than enthusiastic in their support of such efforts.

Use in Setup Time Reduction

Setup time reduction is probably the first type of project in which it was systematically used, first because the high stakes justified the cost, even in the 1950s and second because its objective was clearly to make drastic changes in activities that were not production and not to nibble a few seconds out of a repetitive task by pressuring a worker to move faster.

The Vanishing Cost of Shooting Videos

Technically, the cost of shooting videos has not been an issue since the advent of the VCR in the 1980s. Analyzing a video by moving forward and backwards on a cassette tape, while it appears cumbersome today, was far easier than dealing with film. The collection of data on electronic spreadsheets also eliminated the need to use counterintuitive time units like “decimal minutes.” Adding columns of times in hours, minutes and seconds was impractical manually but not a problem for the electronic spreadsheet.

With videos now recorded on and played back from flash memory, and free media-players as software, not only is moving back and forth in a video recording is easier, but the software maps video frames to the time elapsed since the beginning. We could manually transfer timestamps read from the bottom of the video player software window into electronic spreadsheets and have the spreadsheet software automatically calculate task times as the differences between consecutive timestamps.

Analyzing Data in Video Form

While this approach has been a common practice for the past 15 years, video annotation software is available today, which helps break down the video into segments for steps, label them, categorize them, and analyze them.

You can also use it to structure the data and generate a variety of analytics to drive improvements or document the improved process through, for example, work instructions. Over the previous approach, video annotation has the following advantages:It automates the collection of timestamps. Reading times on the video screen and typing hem into an Excel spreadsheet is tedious and error-prone. Plowing through the details of a 30-minute is tedious enough already.

  1. Within the annotation software, each video segment remains attached to the text, numeric or categorical data you attach to it. One click on the data brings up the matching video segment.
  2. Using parallel tracks, you can simultaneously record what several people and machines do. Of course, you can do that without annotation software too, but it is more difficult.
  3. You can still export the data you collect and analyze it in Excel, but you can also take advantage of the software’s built-in analytics.

“Video time studies” is too restrictive a name for what we do with videos. It implies that they are just a replacement for a stopwatch in setting time standards. But what we really do with videos is analyze processes for the purpose of improving them, and this involves more than just capturing times. The primary pupose of the measurements is to quantify the improvement potential to justify changes, and to validate that they have actually occurred.

Remaining Challenges

Putting this technology to use is not without challenges. Video files are larger than just about any other type we may use, be they rich text, databases, or photographs. And they come in a variety of formats and compression methods that make the old VHS versus Betamax dilemma of the VCR age look simple. More standardization would help, and will eventually come but, in the meantime, we have to learn more than we want to know about these issues. Functionally, the next technical challenge is the organization of libraries or databases for storage and retrieval of data captured in the form of videos. The human issues of video recording and analysis of business operations, on the other hand, remain as thorny as ever.