Activities in routing

1. • Determination of what to make & what to
buy
•Determination of material requirements
•Determination of manufacturing
operations & their sequence
•Determination of lot sizes
•Determination of cost
•Determination of scrap factors

2. Routing Decisions
 Analyze the product
 Make & buy decision
 Material form, shape & quantity
 Planning the operations
 Routing or operation layout
 Planning of an assembly

3. Line of Balance
Line of balance is arranging a production line so that,
there is an even flow of production from one work
station to the next, i.e., so that there are no delays at
any work station that will leave the next work station
with idle time.
In other words, “the apportionment of sequential work
activities into work stations in order to gain high
utilization of labor & equipment & therefore minimize
idle time.”

4. Objectives of Line Balancing
 To study the progress of jobs at regular intervals
 To compare the actual progress with the required to
satisfy delivery requirements
 To identify those operations in which progress is
unsatisfactory
 To obtain high utilization of labor & equipment

5. Analysis of Line Balancing Problems
 Determine the number of work stations & time
available at each work station.
 Group the individual tasks into approximately equal
amounts of work at each work station.
 Evaluate the efficiency of grouping.

6. Determination of Cycle Time
When the amount of output units required per period
(period may be hour, shift, day, week) is specified &
the available time per period is given (the num. of
working hours per shift, num. of shift per day) then
Cycle time (CT)= Available time per period/ Output
Units required per period

7. Line Balancing Methods
 Heuristic Approach
 Kilbridge & Wester method

8. Heuristic Approach
Heuristic mean to find out things for oneself. Heuristic methods
break down a complex problem into smaller & easily manageable
sub-problems.
Steps-
 Identify the job
 Break down the work into elemental task
 List of the various steps
 Sketch the precedence diagram & mark the task duration
 Find the cycle time. The maximum number of stations may be
equal to as many as the number of tasks or steps.
 Assign task to station- The task is combined to make up their
time closer to cycle time & not exceed the cycle time. For making
total time of tasks equal to cycle time, tasks may be shifted laterally
provided the precedence relationships are maintained.

9. Kilbridge & Wester Method
In this method the nuber are assigned to each operation
describing how many predecessors it has. Operations
with lowest predecessor number are assigned first to
the workstations.