LINE BALANCING

         Line Balancing is leveling the workload across all processes in a cell or value stream to remove bottlenecks and excess capacity. 

Capacity is calculated as 

( Number of machines or workers )×( Number of working time )×( Utilization)×( Efficiency ).

Load level

Why need to do  LINE BALANCE

Line balancing is a 6-step process.

1. Choose a work area : Identifying the beginning and end process.

2. Obtain individual cycle time for each work element for calculation:

     Record all tasks of an individual operating into Cycle Time Worksheet.

    Common attributes of cycle time worksheet

    2.1 Product detail(Product group, Style, S/O, Order quantity, Customer name, Shipment date)

    2.2 Date of recording 

    2.3 Recorder name 

    2.4 Station number 

    2.5 Operator name each element 

    2.6 Work elements name 

    2.4 Cycle time data

    2.5 Total cycle time

3. Add the individual cycle times to obtain the total cycle time.

4. Create an Current-State operator Balance Chart.

5. Determine the ideal number of operators by dividing cycle time by takt time. 

    Example   Cycle time = 87 seconds , 

                    Takt time = 42 seconds 

                    Ideal number of operators = 87/42 = 2.07 operators

6. After complete the Current-state operator Balance Chart necessary to meeting for explain the detail to all operators in work area.

Next Step

    - Check the actual output all of element if the quantity of output is not in             accordance with the targets set must be analyzed the causes and                       find methods to improve.

    - Analysis to determine the Value Adding and Non-Value Adding process        Use the Lean tools to eliminate the wastes. For Example MODAPTS

    - Re-balance the process again. For the example, this calculation is as follows:

CYCLE TIME

Objective

1. To compare with takt time and to determine the optimal number of workers needed to complete an operation or process. 
2. Reduce cycle time and develop standard work.

Operating Procedure

1. Check the details related with product and prepare study plan.

• Detail of the operation.
• Detail of material and accessories
• Detail of machine
• Skill of the operator
• Detail of location and environment 

     2. Prepare the cycle time sheet

    3. Prepare the Timer Clock

There are two types of cycle time:

1. Individual cycle time :The rate of completion of an individual operation ; for example, packing or welding.
2. Total cycle time :The rate of completion of process of operation. You calculate this number by adding together all individual cycle time in given process.

How to check cycle time

1. Start to check individual cycle time  from first process.
2. Start records began moving from the normal position to pick up the pieces to complete one cycle.
3. The number of recording cycle time working depends on the desired resolution. Usually it takes 25 cycles or more to enable such information to be used in the statistical analysis.
4. After completing collecting all the data we could find a number of employees we need in each processes and total cycle time.

EXAMPLE 

Working hour = 8 hours , order = 7,200 units and working day = 10 days

From question 

1. Working hour= 8 hours x 60 minutes x 60 seconds = 288,000 seconds 
2. Order = 7,200 units
3. Working day = 12 days
4. Downtime = 60 minutes per day = 3600 sec. per day

Takt Time =  (288,000 sec. - 3600 sec.) x 12 days / 7,200 units = 42 sec. 

So customer want 1 unit every 42 sec.

Operation Process Control (OPC)

Cycle Time data

The graph shows a comparison between Individual cycle time and Takt time

Next step

• Determining the optimal number of workers is calls line balancing. It is the process by which you evenly distribute the work elements among all operators.
• Process analysis to determine loss and utilize kaizen activity to reduce cycle time and improvement.