Work Measurement PFC & Time Study Webinar

Work Measurement PFC & Time Study Webinar. Rev-1.1.

[Audio] The content that we will cover in this webinar are as followed: Definition Objectives Material Management Supermarket Material Replenishment Constraints Kanban Layout and Material Flow Rack and Trolleys design Summary.

[Audio] What is Material Replenishment? Material Replenishment is the system of moving upstream material (from the warehouse) to downstream value add processes (our workcells and workstations). The purpose is to keep material flowing through our value stream to feed the manufacturing lines in order to meet our customer demand. In Jabil, we will consider material to be actual WIP products, raw materials we build into the products, and sub assemblies waiting to be built into a chassis for example..

[Audio] The main challenge with a material replenishment system is it involves many functional groups to get material from the warehouse and to the workstation – this requires exceptional communication and coordination between teams. If material is missing, a wait occurs and time is wasted. If the material handler gives too much material, it can cause confusion to where it was placed. Ultimately, the material replenishment system has the potential to result in poor customer service if deliveries are missed due to materials. Defining a well structured material replenishment system can: Reduce Inventory on the floor Increase Floor Space Reduce Headcount Eliminate line stoppages and production downtimes and To reduce Cost.

[Audio] There are 2 common systems available: Push and Pull… A Push System is where the material replenishment is based on a fixed schedule. Whether you used the material or not, the material handler will come to push material into the Workcell. A well prepared detailed schedule for every operation and job order is required. For example, we replenish every X hours or we kit the material to exact for each assembly job. A Pull System is where replenishment of material will be carried out as the Workcell requires it – this is a Key Principle of Lean. A Pull System could utilize a supermarket and first-in-first-out concept, or a Kanban. For example, we only replenish the material when the material level hits the minimum level and a signal is sent to replenish it..

[Audio] For a Push System, Material replenishment is usually direct from the Warehouse to the Workcell. Where do we stage all the materials? It will be all over the production floor if the Workcell does not need it, and additional space may be needed for material staging. The layout would look very chaotic! Also, the material handlers need to travel from warehouse to workcell for each material replenishment… this can cause fatigue and communication errors in the long run. For a Pull System, we create supermarkets for the material staging on the production floor. Then, we only replenish whenever required. Therefore, less space is required because it is visually organized. Material Handlers will ideally travel with shorter distance. Additionally, the pull system promotes visual communication, because the material handlers can see exactly what material needs to be replenished..

[Audio] A third system can be created by combining the Pull and Push Systems. There are a few combination options on how to do so. One example is to replenish the material from the Warehouse to the Supermarket in every X hours – a push. Then, we replenish material from Supermarket to Workcell as required – a pull. Jabil's business environment has changed dramatically in recent years – there is increased competition, wider market range, and higher expectations from our customers. Thus, we must design our systems to lower total costs in the supply chain, shorten lead times, reduce inventories, and improve reliability of deliveries… while maintaining a high level of customer service and quality. So, it is very important to design the most efficient & effective material replenishment system that fits our needs..

[Audio] On our manufacturing floors, we commonly have a push and a pull system. Keep in mind, the products we are producing, or WIP, is considered material as well. SMT is ran off of a forecasted schedule, and thus, pushes the WIP to queue up in a supermarket – this happens regardless if the Workcells can accept the work or not. However, our Workcells have a set demand, aligning more with our weekly customer demand thus, they pull WIP as needed. To note, we must align to our customer demand, with production, and the raw materials being consumed in our value stream system!.

[Audio] (USE LASER POINTER FOR THE WHOLE SLIDE) The advantages for a Push System are that the material is always available, and also there is minimum communication is required between the different functions. While for Pull System, the advantages are the Material Handler only replenish when the inventory hits the minimum level, it require a smaller space for material staging, lower inventory, minimize the need for a detailed schedule for every operations and job order, and it promotes a FIFO system. A Push System's disadvantages include that a Material handler is required to replenish the materials even the material usage is low during downtime, it requires more space for material staging in production, higher inventory, we need to create a detailed schedule for every operation and job order, thus we might missed the replenishment schedule, and also difficult to control a FIFO system. In a Pull System, the disadvantages include that frequent replenishments may be needed if the product has short cycle time and/or large parts, also, we need a communication system to be established to replenish material so the risk of slow replenishment is avoided that might lead to production downtimes..

[Audio] So which system should we use? It depends on the demand or our customer's business model. We will look at two example scenarios – the first is For High Mix, low volume We combine the Pull and Push Systems by setting up 2 or more Supermarkets for non-common parts (or possibly kitting to exact builds), and one supermarket for common parts (such as bulk materials like screws). Supermarket 1 is for the first job order, Supermarket 2 is for the next job order. The reason why we have 2 supermarkets for non-common part is to avoid time lost due to changeover between assemblies on the same line, as this is high mix low volume. We are able to kit to exact if the job order size is small enough and space required is available for storage. If we do not have enough space or the job order size is too large, then we may have to replenish more frequently. Supermarket 1 and 2 are replenished every X hours to kit the job orders, while common part are replenished as required. This will save work for constantly kitting common parts inside kits, and also avoid flooding the supermarket with all of the material for one job order. Also, supermarket 3 could be shared with other workcells using the same common parts. As for the Workcell material replenishment, we will pull to replenish as required. You may notice that Supermarket 3 has the indicators green, yellow and red… These are the indicators of the material inventory level. When it hits the yellow zone, it means it is time to request for material replenishment before we run out of material..

[Audio] Now lets take a look at a second example for low Mix, high volume. For this situation, we can fully use the Pull System. Based on the number of workcells, we can Setup only 2 supermarkets, one for non-common parts, and the other for common parts. Supermarkets for common parts usually are shared for a few workcells. Then we can replenish it whenever it hits the minimum level from Warehouse to Supermarket and the minimum level From Supermarket to Workcell. Remember, this will be more aligned to our customers daily and weekly demand..

[Audio] What is a supermarket? A Supermarket is not just inventory & WIP. It is controlled inventory & organized WIP according to a workcell's demand consumption. A supermarket promotes the following: The materials are split by part type (for example : common versus non-common parts, physical part sizes, workcells and the parts are delivered & organized) Then we have FIFO (first-in-first-out) under more control. A part leaving the supermarket gives a signal for replenishment or delivery of more materials because we can visually see that the part has been consumed..

[Audio] What situations require a Supermarket? Here are some important examples… (USE LASER POINTER) A shared line splits into dedicated Workcells (for example, in between SMT to Backend) When 'flow' is not possible due to disconnected processes; in other words, in between lines where we do not have continuous flow High demand variability environment – this could be our customers business model High mix lines with small batches Warehouse to workcell replenishment cycle is too long because the travel distances are too far – this is common constraint in many sites. Keep in mind, a Supermarket is not always necessary! If you have a true pull system where WIP is truly controlled and constricted to only entering the system if another unit exits the system… then Supermarket may not be needed..

[Audio] So how do we create a Supermarket? First We define the lines that the Supermarket will serve: Name(s) of manufacturing lines Assemblies that run on the lines Daily/weekly/monthly demand UPH for each assembly Secondly we establish the Replenishment frequency Rate the line will need material Rate to restock the Supermarket Material Handler availability MFG Line Leader availability Lastly we carry out the physical design : Layout location of Supermarket Rack & trolley design Spaghetti mapping delivery route Replenishing the workstation But this is a cross functional effort, for example, we need: Industrial Engineer Line product Engineer (IE/ME) Planning Inventory Control and MFG Supervisor/Leader Great cross functional teamwork makes a material replenishment system successful..

[Audio] Lets look into how to define the supermarket size… (USE LASER POINTER) The Demand rate is the rate at which inventory is consumed, or more specifically, it is the UPH multiplied by each individual part required for one unit of a product. Replenishment Time is the initial interval time required of when to replenish material. Minimum Inventory Level, or M-I-L, is the percent of inventory that exists for material handler to kit and deliver material and also to protect against downtime; this is commonly referred to as safety stock. In this example we will assume the demand rate is at 5000 units per hour. In other words, we will assume a single part is only used once to assemble the unit. Replenishment Time at 0.5 hours and Minimum Inventory Level at 20% Supermarket Size = Demand Rate * Replenishment Time * (1 + Min Inventory Level)… = 5000 * 0.5 * (1+20%) = 3000 In this example, we will assume there are a total of 5 parts to build a single unit. Therefore, the Total Supermarket Size = 15,000 units This means we need a physical space to keep 15,000 of parts Also, we need to consider the bin capacity. The bin capacity is how many units can be built with the contents of a single bin; in other words, a single bin can hold enough raw material to build 100 units, for this example. The Bin Quantity = Supermarket Size divided by the Bin Capacity So, 15,000 parts / 10 units of bin capacity means we need a total 1500 bins for our supermarket to work if we were to replenish it every 0.5 hours from the Warehouse into the supermarket while the Workcell is consuming at a demand rate of 5000 per hour. From these calculations, we can calculate how big is the space required, or rack or trolley needed, based on how big the physical bin size is. Different material will require different bin sizes. In this example, the numbers might look to be a lot of bins… this is due to a 12 hour replenishment time at a 40 units per hour demand rate. You may need to calculate different supermarket size scenarios to see what works best cross functionally and it also depends on how big is the space available. Also, we often work with small parts… so the physical bin size might be small as well!.

[Audio] How about Supermarket size for Workstation : Generally, it depends on the workstation space… usually we need to maximize the material quantity but without compromising safety and workstation ergonomics. Normally the initial replenishment time is every 2 - 3 hours. This is a guideline and can quickly change based on how much available space these is, how small or large the parts are, and based on the standard work defined for the workcell. The best practice is to consider the space for material when we design the workstation in the early stages of line design..

[Audio] What are the constraints we might have? Large parts : Usually when we must assemble large parts, such as a large chassis, the cycle time is much longer… and it is not possible to store much material at the workstation. But in-order to produce units efficiently, we can setup the Supermarket near the assembly stations and then allocate a space for the large material nearby. If possible, the large parts could stay on a trolley to effectively move around and replenish more efficiently. Layout Space : We can setup smaller supermarkets if there is a physical layout challenge, and not enough space to store it effectively on the production floor. For example, reduce the initial replenishment time from every 12 hours to 8 or 6 hours. Keeping in mind, this would increase the work load for material handlers and we might need to add additional headcount. Another reason why a material replenishment requires cross functional involvement..

[Audio] What is a Kanban? A Kanban in Material Replenishment is a tool to help to manage replenishment of the supermarket and the workstation. A Kanban is the method of when to replenish the supermarket or workstation via use of a visual or digital indicator. It could be a traffic light system, milk run delivery method, or a combination of these systems. There are many effective methods to execute a Kanban system – even a clearly visual empty bin could be a Kanban!.

[Audio] Here are a couple examples of a Kanban method to call for material replenishment. Traffic light system : Whenever the material level at the supermarket or workcell hits the warning level, or the yellow light, then material handlers need to start the process to replenish the supermarket or the workcell. Another example is the Milk run delivery method : This comes from the concept of Replacing empty milk bottles with full bottles during delivery. Similar to our production floor, we deliver and replace the materials in new bins and collect the empty bin at the same time. It may be possible that the material handler can quickly empty the de-trash baskets as well..

[Audio] The examples mentioned on the previous slides required a lot of communication and it is managed manually, which means it require a lot of attention from the employees. So there could be risk of communication error that could lead to line stoppages and downtimes. These can be improved by implementing digitalization and automation into our processes. For example : Smart bin system Put To Light Stocking and Replenishment; Install a digital system that makes communication easy between production and material handler by just pushing a button. After determining our Supermarket Size and Kanban method, we will now explore options of where to physically place your supermarket and how to design the Kanban replenishment path..

[Audio] The overall Layout and Material Flow will be highly constrained based on the location of the warehouse and existing infrastructure. However, since a Supermarket Size can be strategically adjusted, there are many opportunities to place them throughout the manufacturing floor. Here is one of the example of a material flow layout. SMT is on the left, the backend workcells are in the middle, and the warehouse is located on the right We must first strategically decide where to place our supermarkets given the available space… as SMT runs a much faster rate than the backend Workcells, plus, we have 3 SMT lines feeding many more backends… this is a good opportunity for at least 2 Supermarkets. Off line feeder setup is a common for SMT, and we will need another material replenishment Supermarket for the backends – which is placed in the middle (it could also be off to the sides as well). We first must design the route to move material from the Warehouse to both of the Supermarkets in scheduled intervals – this will likely be at least 2 different material handlers. Next, the path for the material handler to move material from the Supermarket to the workstation. SMT is quite strait forward as materials go into our placement machines. The backend workcells will require a longer path to serve all of them – it should be circular in path design. Finally, we must return empty feeders and bins back to their original Supermarket – again, this should ideally be a circular path design for the material handlers to reduce waste..

[Audio] A workstation material replenishment should have a similar concept of receiving and delivering… The most ideal situation for material replenishment is at the back of the workstation instead of in front as you see from the red arrows. This would not interruption production. So we need to design the workstation, and also proper aisle spacing, that allow us to replenish material from the back of the workstation. Some good points by replenishing from the back are It Does not interrupt production builds More Effective for material handler to replenish material as they do not need to wait for operator to finish up the work. Some disadvantages are: Requires more space for the material handler to deliver the material Large parts and sub assemblies usually can not fit into the workstation from the back.

[Audio] When the floor layout space is constrained and needed for more production workstations, it is common to place workstations back to back to eliminate the extra aisle space that was used for material replenishment… we will have some considerations to make... If we are not able to design the line to replenish the material from the back of the workstation, then we need to factor in the time lost for production due to material replenishment. Either our standard time will increase from non-cyclic events, or there will be a brief downtime event that is recurring in nature. Or, it is possible to design a side rack for the material so that we do not interrupt the line; or at least minimize the operator disturbance time when replenishing material..

[Audio] A Gravity flow rack, designed with good ergonomics can offer fast-speed replenishment. Great concept for supermarket racking system for replenish and return. This can be adapted to feed a workstation as well at a smaller scale. Multiple bin size trolleys for material replenishment at one go to deliver new bins and parts while collecting the empty bins. This idea can also be used for a bulk material rack that is stored directly in the workcell. The design is based on the Site's needs from customer demand and part sizes; and engineers need to select or design the right rack and trolley..

[Audio] A good Workstation design allow us to replenish and collect empty bin from the back of the workstation. Also, it is common to place empty bins underneath the workstation to return back to the material handler. A side rack is a possibility for additional material, or for a workstation that's not able to replenish from the back. Here is an example of a trolley rack design which makes it easier for operators to unload by laying the bin slanted at 45 degree. While picture on the right, the bin with material laying flat on the rack, creates difficulties to load or unload the material into the bin..

[Audio] Sharing best practices is an effective way to improve the performance by repeating the best practices in our organization. So after we had done a great improvement on the Material Replenishment, we can document the practices by: Managing the Supermarket Replenishment procedure: Define the roles and responsibilities for maintaining the Supermarket Demand Rate & total number of bins Operation/Material Flow Guidelines – these are standard practice that existing and new material handlers, line leaders, and operators should follow to execute effective material replenishment Also, include what bays and lines the Supermarket serves… This can be maintained in your sites Document Control system, and also a good practice to display it directly on the supermarket rack or trolley. Additionally, we need to document the Workstation Material Layout for Replenishment: A Workstation material layout picture It is a best practice to document the workstation material layout as first page in the Visual Aid for each specific assembly. Ideally a picture of the workstation with the location of the raw materials clearly labeled is a good practice; especially for a mixed assembly line. And don't forget to put a note on how the operator should return the empty bins With this documentation, then we can maintain and continue to improve our baselines. This documentation can also be used as training material for new employees to the work area..

[Audio] Lets now summarize the benefits of creating a good systematic material replenishment management system… We will have: Better Material Flow by making it part of our standard work. Which will allow for more Effective Inventory Control And Improve the efficiency and help to reduce fatigue of our operators and material handlers. We will also Free up space for production line And Eliminate Non-Value added processes/operations Thus, there is opportunity to Reduce Headcount And Eliminate line stoppages and production downtime events. Altogether, this will help us Reduce our Costs And allow us to create an optimized material replenishment system to better serve our customers..

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