Polyhedrika

  When we need to process different products in the same line we want to work out the best job sequence to minimize lead time and maximize capacity utilization. We also need to work out the minimum lot size to meet the demand and minimize lead time. Before we can commit the delivery date of a new job to the customer we need to know the  state of the jobs already being processed For non repetitive processes you can use project management scheduling The ideal of "Lean Production" is lot size of 1 but this is not always possible when change-over time is significant. This change-over involves loading different components and changing jigs or molds. When change over or setup time is significantly higher than process time we are forced to work with larger lot sizes. One way to minimize lot size is to minimize setup time. The SMED (Single Minute Exchange of Dies) methodology has been very successful to reduce setup times from hours to minutes.  Scheduling Constraints In a sequenti

  Test and Repair are Non-Value-Add operations: defective products should not be produced on the first place. Unfortunately the state of the art in many processes is not there so tests and controls need to be part of the value stream.  Ideally as the value stream becomes more robust some of these controls can be removed. On the mean time we need a test and repair plan (if repair is possible). A Test/ Repair loop can become a bottleneck for the whole Value Stream when Test First Pass Yield is lower than planned. A drop in FPY is normally caused by problems upstream in the Value Stream as seen in   Defect generation and detection Test/ Repair loops are often absent in Value Stream Maps in spite of the potential to become the bottleneck for the total process. Download this Excel example file   TestRepair.xlsm   to your PC from OneDrive folder   Polyhedrika You must close all open Excel files before you open this one and you should enable Macros . To simulate 1 hour operation just press  F

  Post-Its were introduced in 1977 by the company 3M   and since then they have been used in the whole world in all sort of different areas: home, office, factory, etc. In the area of process improvement they are widely used for: Brainstorming Cause & Effect Diagrams Value Stream Mapping Storyboards Job Scheduling The method used in these work groups is to have participants write their ideas in post-its and stick them on a board or wall for everyone to see. Advantages of this Approach: All participants write at the same time so you can quickly gather inputs from everyone It doesn't require any special skills Post-its can be easily moved or grouped together by the team The overall vision of all these ideas generate new ideas or solutions in the team It enables interactions among the members of the group Some Limitations: The size of the post-it may constrain the description of some ideas Hand writing of the participants may not always be readable by others, specially at a distan

  Since 450 BC King Solomon realized the importance of the right time for everything.   Time is often critical to our success in daily life. Following the right sequence of the different activities is also key. Time is critical to any process, whether it be manufacturing, sales, distribution or business processes. Value Stream Map : Who Does What and When When several people are involved in a sequential process each one needs to know when he needs to do something. Synchronization is key for success. A value stream map defines the right sequence of activities and who does what.  Job Scheduling In addition to defining the sequence of operations we should be able to plan when each one is involved therefore we need to know the time each job it will take.  In a sequential process a delay in one of the steps causes a delay to all following steps so this requires a reschedule of the value stream and a quick communication to all those involved in order to react. Time Measurement Time is a var