Jun 4 2013
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:
- Place components on fixture.
- Unload previous unit from the machine.
- Load fixture with new unit on the machine.
- 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:
- Bring carts of stanchions from storage to the reception area.
- Erect the barriers.
- 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.
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:
- The cart is tall and the pusher can barely see over the top.
- The four wheels swivel freely, which makes the cart difficult to steer.
- Without a door-person to clear the way, the cart would have to stop and go multiple times.
Figure 2. Cart with stanchions at museum
During the erection of the barriers in Figure 3, the team makes the following comments:
- The stanchions are held horizontally in the cart but used vertically, which requires extra handling of these 30-lb parts.
- 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.
- Pulling the belts between stanchions is done separately from setting them down.
- Some stanchions are not located properly and rework is necessary.
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.