Snack Rack Processing Experiment

• published: 29 Jul 2015
• views: 135

I am making the same product with different materials and construction methods. I made a previous video and timed the process. Now I have some new ideas to try, but in order to really determine whether an improvement is made, I have to time it accurately and compare the results. So here are those results in reference to the data charts at the end of the video... Conclusion: The "New Process" is not that much faster (about one minute difference when relative steps are compared... see Chart 9) Chart 1) Process Time..... this is the time for each step displayed in a pie chart. This time is recorded by video and the parts counted and averaged to get individual process times. This time does not included breaks or set up time, just the time using the machines and moving material at optimum efficiency. Chart 2) Total Shop Processing Time.... The chart includes the sum of all the steps in Chart 1 plus the additional time factors that take up operational time in the shop. These extra time factors are not recorded, but estimated... so there is some "fudge factoring" and guesswork involved. The sum of Chart 2 provides an estimated value of the total shop time to build the product and get it ready for shipment. Chart 3) Material Cost.... note: The cardboard used to package these products was salvaged from other local businesses, so the material cost for this is zero but I factored in some extra time in the packaging process to account for the extra time. (although the one place is literally right next door so salvaging is convenient.) Chart 4) The results for this production run of 20 racks. I did a little bit better than the last small production run for this product.... but how much better and where? The next charts will compare this data. Chart 5) The "Old Process" pie chart from last year's video. Chart 6) Comparison of two pie charts.... I added in the value in the black color to show the time saved difference for the new process results. Note that I was more liberal with my time estimation for "break time" in the new process. Chart 7) Bar graph comparison for certain steps. This shows where I gained and lost time. The fist data entry is for "Making Parts". This is the time to machine lumber into their finished dimensions. The time for the old process is lower than the new process. This is the drawback of using rough pine wood. Some boards required 3 passes on both the jointer and planer because the surfaces are very uneven. Framing lumber from the old process is factory milled and requires only one pass and is less work. For "Mortising the Sides", the old process was again faster, contrary to what my initial prediction, but not much difference there. However, the router method made a big mess that required extra clean up time. The "Tray Assembly" showed a big gain for the new process, with pocket hole joinery winning the race by a long shot. However, most of the time savings in the new process came in the finishing and packaging steps, both of which are the biggest time factors in the whole process. Chart 8) Comparison pie charts for just the tray making process, showing the gains that the pocket hole assembly method made over the old process of clamping. Chart 9) Another bar graph with all the steps in both process that are relevant to show how the two building processes compare. I left out the final assembly and finishing and packaging steps so I can get a comparison on just the woodworking aspect. I also left out the 1/16" round over on the trays because this is an extra step I did for the new process. (it took around 2 extra minutes for each rack). I left the edges sharp on the old process which saved time but made splintery edges which caused minor hassles with finishing and handling. So the idea to add in the extra routing was a quality control decision, and I may or may not continue it in the future. The results showed that the two processes were fairly close. The gains I showed were mostly due to getting better at the finishing and packaging processes. Also, I determined that the boxing process is more efficiently done with two people, which saved some time in the new process. Before, I boxed the product by myself, and this involved some extra handling and clamping.