May 31 2013
Using videos to improve operations | Part 3 – Shooting shop floor videos
Following are a few recommendations on the art of taking shop floor videos:
- 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.
- 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 interferenceThis 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.
- 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.
- 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.
- 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. - 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.
- 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.
Jan 7 2014
Using videos to improve operations | Part 7 – Detailed review of process segments
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:
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.
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.
While conducting the analysis, do the following:
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:
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.
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:
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By Michel Baudin • Technology • 2 • Tags: Assembly, Excel, industrial engineering, Lean manufacturing, Productivity, Spreadsheet, Video