Value Stream Mapping Train the Trainer
Information For A Process Data Box (to be collected on the shop floor) Cycle time Changeover time Process reliability (uptime) Scrap/Rework/Defect rate Number of product variations Number of operators Production batch sizes Working time (minus breaks) Pack size
Typical Steps to Complete a Current State Drawing Document customer information Complete a quick walk through to identify the main processes (i.e., how many process boxes) Fill in data boxes, draw inventory triangles, and count inventory Document supplier information Establish information flow: how does each process know what to make next? Identify where material is being pushed Quantify production leadtime vs. processing time
Frequently Asked Questions: Make to Order and Engineer to Order Shops Many shops have a combination of repetitive and non repetitive products (indicating product families) Product families might be difficult to see focus on machines/operations and work content time Engineering might be included in the information flow for leadtime impact, etc. Pitch is typically arbitrary to the manager Employment of pitch requires detailed knowledge of work content and routings for jobs
FAQ: Distribution Centers Example (Information flow on top) I RECEIVE STOCK PICK PACK SHIP I I I I
FAQ: Parallel Manufacturing Flows Keep it simple, and make sure to leave room for the data boxes!
FAQ: Including Subassemblies FAQ: Including Subassemblies Focus on major subassemblies first Select one or two which might represent different types of situations Generic vs. specific to the product family Outsourced tasks within assembly Follow the format for parallel flow, and always include the main assembly process! For large fabricating and assembly operations, consider maps for each major subassembly with a macro map indicating the entire product family
FAQ: Do We Really Have a Supermarket (or FIFO lane)? Supermarkets (and FIFO lanes) control production between points of flow without a written schedule. What is the trigger for production in this area of the value stream? Is the upstream process overproducing? If there is a scheduling system present outside of a pure pull, chances are that there is no supermarket.
FAQ: Outsourcing FAQ: Outsourcing I Mon + Wed XYZ Corporation Mon + Wed I 300 pieces C/T = 1 hour 100 pieces L/T = 3 days Batch = Min. Batch = 2 days 3 Days.7 days 60 min.
FAQ: Long Processing Times vs. Production Leadtimes I 300 pieces CURE I 100 pieces C/T = 8 hours C/O = 25 min. Rel. = 100% Batch = 100 pcs. 3 days 8 hours 1 day 8 hours
FAQ: Cycle Times vs. Work Content Work content is important to understand costs and in balancing flow Consider all machine and manual work content, regardless of the cycle time Accumulate all parallel operations in the processing timeline ASSEMBLY C/T = 30 sec. C/O = 25 min. = 5 Cycle Time = 30 sec Work Content 150 sec.
FAQ: Different Changeover & Cycle Times, etc. Current state mapping might uncover: Several different machines performing the same operation Different products within the family with different data box characteristics for a specific process Capture the range of values as opposed to an average value
FAQ: Mapping Final Inspection/ Repair/Rework Judgment counts! Minimal repair/rework might be captured as a data attribute at the final step. If nearly every part needs assessment or extra work, consider a separate process box.
FAQ: Supplier Data Boxes FAQ: Supplier Data Boxes Data attributes are dependent on the value stream and supplier. Minimum information might include: XYZ Supplier L/T = 3 weeks Batch = 3 Tons Min. Batch = 2T 2% Scrap
FAQ: Pull Within an MRP Environment A combination push and pull is usually just a push system! Multiple production triggers typically lead to overproduction.
FAQ: Assemble to Order Options in a Future State Finished goods supermarkets can be expensive in value streams which have many finished part numbers within a product family To minimize inventory costs, try to find the upstream location where the value stream has very few variations and consider a supermarket of WIP at that point. Customers orders can drop to this location, with FIFO lanes controlling production into shipping.
FAQ: Assemble to Order Options in a Future State OXOX Customer Orders CUT max 20 pieces ASSEMBLE max 20 pieces SHIP F I F O F I F O
FAQ: Why Not Just Start Pulling Tomorrow? Initiating a pull system without first attempting to flow will result in lots of supermarkets, and may increase your inventory levels. Design your future state with the following sequence: Flow wherever you can (while still pushing) Produce to the TAKT (while still pushing) Implement a pull system
FAQ: Administrative Mapping: Part 1: Integrated Include functions such as engineering, purchasing, and order entry for product families which have routine activities prior to scheduling Place the process boxes between the customer and the scheduling function Minimize the data collection to the basics of cycle time or quality, and document the impact on leadtime
FAQ: Administrative Mapping: Part 2: Separate Maps Better for redesigning overhead and administrative support areas touching value streams Order processing Warranty activities Job quotes Not useful for activities outside a value stream Data boxes must have attributes focusing on cost, quality, and service Inventory is typically paperwork Information flow is typically informal