 Hello friends, today we will have line balancing as our topic for discussion. As you know, production planning and control involves various stages like routine scheduling, machine loading. When it comes to machine loading, naturally there is a question of line balancing because process time for the jobs vary from machine to machine and also the process time varies from operation to operation depending upon the contents of that operation and as well as the accuracy and the specification required for that particular operation. Therefore, line balancing is a very important aspect mainly used in the mass production and at the end of this line balancing session, all of you will understand what is the concept and method of line balancing and at the same time, you will be able to differentiate between balanced and unbalanced line. The contents are what is the definition of line balancing, what is the concept of line balancing, methods of line balancing, balanced and unbalanced line, what are the typical features of balanced and unbalanced line that we are going to discuss today. Line balancing, it is a simple means of balancing the production line or an assembly line, what that means probably will be clear to you in the next slide as we are explaining with a simple example. The main objective of the line balancing is to distribute the task evenly over the workstation so that ideal time of the main and machine is minimized. Another entire focus of all production systems or operation systems is that we have to increase the profits of the organization by meeting customer demands, customer satisfaction, delivering all the required goods and services on time with the required quality and quantity and at the predetermined price. So, therefore, any method of line balancing or any method of any other technique are ultimately aiming at optimum utilization of the available resources and ideal time or wastage should be as minimum as possible. Of course, line balancing is one of the attempts in that direction only. It aims at grouping the facilities and workers in an efficient pattern in order to obtain an optimum or most efficient balance of capacities and flow of production, assembly or processes. It can be assembly line balancing or it can be a machine or process line balancing. Tasks are grouped so that their total time is preferably equal to or a little lesser than the time available at each workstation and therefore try to reduce the ideal time of the entire jobs. What that means? This means now it is a very simple example. Because there are three workstations. Now, what is the meaning of workstation? We will discuss first, workstation is the group of various resources. It may be machine, it may be equipment or it may be number of machines or it may be machine plus some inspection table or machine plus quality checks. All that taken together we are forming a small group of various resources and then calling it as a one workstation. It is a convenient method of making the groups of the available facilities so that amongst that you are dividing that particular work into small workstations we will be able to calculate the time required for each workstation and thereby we are trying to aim at the time required for the each workstation will be almost equal. If not exactly equal we are trying to see almost equal and this time is equal to the time required by the bottlenecking or time required for that particular resource which consumes highest time or the longest time. Now this is a simple example where there are three workstations or for convenience we can make for the for a moment you can think of three three machines. Machine number one, two, three and then for the process time for each of this is the machine number one has having two minutes, machine number two is having five minutes and machine number three is having three minutes. And suppose I want ten pieces of this at a regular production flow then of course how that will be determined now the entire output of this three line machines will be dependent on only the bottlenecking that is machine number two which is taking more time in terms of the processing it takes five minutes whereas machine number one and machine number three are taking two minutes and three minutes each. Now I have to balance this line there can be number of alternatives for the possible one simple way of make it is that combine machine number one and three and then probably you can get the equal time only thing is that this will result into backtracking of the material once again but it will definitely have a balanced line as such therefore now replace the world machine by workstations then we will be able to apply the meaning of line balancing in a broader sense. Now in the initial way we have thought of machine now we can talk of workstation workstation can be combination of various resources so what is bottlenecking the workstation that takes longest time is called as bottlenecking bottlenecking decides the entire output of that particular line how much time the bottleneck takes that will be the ultimate time which is required and that decides the total output current cycle time it is the same as the bottlenecking time and the flow time is time to complete all the operations on all workstations now for example here the flow time is equal to 2 plus 5 plus 3 is a total minutes the current cycle time is of course five minutes that is the cycle time which is on the bottlenecking machine there are some diagrams which are used for this line balancing one is called as precedence diagram which shows network of tasks and restrictions on their performance because we cannot do any activities in isolation each particular activity or each particular job has to have a some precedence it depends upon some other prior operations and also some operations need to be complete before that particular job goes to the next operation total work content is the sum of total task times for all the production tasks for that particular product and now this will give a formula for minimum number of workstations that is total work content divided by cycle time total work content is x and in cycle time is the total longest time on that particular various activities is the total now what is a balance line and what is a unbalanced line this look to this figure this figure is there are total four workstations and 15 minutes 15 minutes 15 minutes and the last workstation takes 10 minutes so these are the various time required resources for the various workstations and probably we can call it as a fairly balanced line because the first three workstations have almost equal time and the last workstation has a small amount of balance unbalanced which is remaining over there this is an example of perfectly balanced line what are the benefits of this perfectly balanced line is that it promotes single piece production flow Toyota production system has used this term as and the same concept is also even to lean is that it promotes single piece flow instead of a bus or batch we are talking about a single piece it also avoids overburdening at a particular resource and it will try to minimize the seven Toyota production system has defined the total time of total types of waste as seven types including overproduction or including delays including scrap or the rejections it can be waiting so all it can be inventory all these types of waste are there when you have got a balanced line of course we are not reducing only one type of waste we are trying to focus it at all types of waste reduction is possible and ultimately when you aim for zero defect further to zero defect it is trying to reduce the variation part to part variation is reduced when you are trying to achieve a balanced line as such and the contrary if the balance is not there it is unbalanced line now unbalanced line this example is giving that first workstation takes five minutes second workstation takes 25 minutes the third workstation takes 15 minutes and the last workstation takes 10 minutes if you observe it over here workstation number two is the constraint which is the cycle time which decides the entire flow of the output of this particular line now if you just see over it over here is that since the workstation number one is having only time of five minutes process time of five minutes and therefore at workstation two there is a heap of inventory waiting for the machine and therefore naturally overproduction of workstation number one will definitely cause other types of waste it also increases the inventory but we have to think of some other alternatives otherwise this will go on increasing WIP will be definitely piled up before the constraint machine is just obvious phenomena now if you look to the third case it is again a different story where the operator has to wait because this taking more time and the operator has no work to play therefore he has to wait and again it results into another type of waste waiting waiting for the job to be completed in the previous machine or previous workstation similarly if you look at this here 10 minutes again the time required for this 15 minute is more and as compared to the last workstation which takes only 10 minutes also here we'll see that the operator has to wait until operator at workstation number three completes all his operations so this is a typical phenomena where we'll see that it is resulting into all types of waste it may be waiting it may be inventory it may be piling waiting of the operator waiting for the job all these things so unbalanced line has lot of disadvantages lot of problems in terms of wastages and in terms of wastage of resources may be material main or machine in this case we will feel that there is a wastage of material and there is a wastage of in terms of inventory in terms of waiting not actually material waste as such and there is also waiting of the operator and waiting of the machines sometimes so that gives you the idea about balanced and unbalanced lines so naturally as a result of this we should always try to have balanced line as far as possible and reduce the unbalanced component to the minimum thank you thank you very much