We're looking at a current state balance of a small assembly line in Assembly Planner's line balancing module and I'm gonna walk you through how to use the automatic line balancing tool. You can first go to the Actions menu and select default balance. There are a number of inputs that you can set to help determine how the line is rebalanced and the first thing that you want to decide is which balance type to use.
You can minimize the number of stations by defining the TAKT time desired. You can minimize the cycle time based on the number of stations available or you can minimize the number of operators. This balance type is a bit different from the other two and that it won't change the task to station assignments but it will help you redistribute your operators. This is particularly useful if you have a highly variable workforce but don't necessarily have the ability to change your task to station assignments frequently.
We'll take a look at the minimized number of stations type and the next thing to decide is which algorithm to use. The weighted average method will set tact with the assumption that some models can exceed TAKT time some models can fall under tack time as long as on average that tack time can be met.
The peak model will set TAKT time so that no models will exceed that TAKT. I will choose a weighted average for now I can input the desired cycle time here if I know that TAKT time. You can also have it calculate your desired cycle time by inputting the line rate the shift duration the efficiency rating and here it's calculated that TAKT for us.
At this point, I'm going to run the balance and come back to the explanation of the rest of these inputs. At this point, the balance is going to run with the precedence constraint. Precedence is a very important constraint and the automatic algorithm will never violate it. You'll see the next thing we talk about are the optional constraints but we recommend first running the balance only considering precedence.
So you can click okay you want to say yes that you can unlock the existing task assignments so that it can move forward with the rebalance and this has produced a balance saying that we can achieve TAKT time of 3.82 minutes with six stations and it's shown how that work will be distributed here.
At this point, we could decide to say well we'd like to see what the balance looks like with five operators, especially because this sixth operator isn't very well utilized. So I can go back to actions default balance and we can switch to the minimize cycle time and we can define the number of stations and input a guess as to what the take time might be with five stations.
Click OK again, and here it's rebalanced that line and we're at a TAKT time of 3.88 minutes and this is again only considering precedence. So at this point I'm going to go back and add in my optional constraints and you may want to add these constraints in one by one to help identify the specific impacts of each type of constraint but take a look at all of them for now and click OK and again it's redistributed the work we're still at five stations but our TAKT has increased slightly to 4.03 minutes.
Those are the inputs that most users use most often you can also choose to introduce increased randomness by adjusting the percentages of the assignment selection criteria. Allow cross station operators will be discussed in another video. You can choose to sort tasks within a station either by the combination of the original operation sequence number and act sequence number or by the activity sequence number alone.
You can choose to have the algorithm optimize the result and find a slightly better result once after it has found an initial balance or continuously during balance if you let it run continuously this could impact the length that it takes for the algorithm to run. You can also change the number of iterations if you want the balance to run a little bit quicker you can decrease the number of iterations if you want to give it more of a chance to find an even better balance then you can increase those inner iterations and you can also change the random number seed to see if that has any effect on your complex balances.