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Production Planning Control - Coggle Diagram
Production Planning Control
planning
to meet the delivery date
ensure
need a a materials for the part of the work
needed tooling
personnel
the information about the product and the end date
scheduling
have the start and completion times for the each shops order
need to develop the load for the work center
implementation
gather the information for the product needed
give the release order to the shop floor, eg MRP authorizes
control
need to control the product order that has been release
action to be taken
rank the order
establish the dispatch list
track all the performance
reschedule or adjust the capacity if it overload
control the work going into and out of a work center : input/output control
Flow Manufacturing
the standard of a products that need to be follow
the repetition and continuous
the work center is arrange according to the routing
limited range of product, specially on the design equipment
use the mechanical transfer devices for the low WIP and throughput times
the capacity is fix by the line
PAC
need to plan the flow works
planned the scheduling the materials to the line
implementation and control are simple
intermittent manufacturing
have variation in product design, process requirement and order quantity.
that have varied in the flow work and it is not balanced
machinery and workers usually grouped according to the function and worker must be fexible.
throughtput time usually long
capacity depends on product mix
consider more on plan and control
no. of product made
variety of routing
scheduling problem
major activity is PAC
project manufacturing
consider one / small number of unit
usually in one place
eg: Shipbuilding
data requirements
total product to produce
part that needed
required more on the operation and items
capacities on the work center
organized into database for planning / control
planning information
item master
part of number
description
manufacturing lead time
lot size quantity
product structure
bill of Material
list of single-level t component to make an assembly
Forms a 'pick list'
routing
instruction to make product
operations and sequence
brief
equipment and accessories
operation setup times
operation run times
lead time for operation
work center master
work center number
capacity
shifts, machine hours and labor per week
efficiency
utilization
average queue time
alternative work center
control information
shop order master, summarize data on each shop order
shop order detail, current record of each operation
scheduling
to meet delivery dates
need info on
routing
capacity
competing jobs
manufacturing lead times
manufacturing lead time
queue - time spent waiting before operation
setup - time prepared work center
run - time to make product
wait - time spent after operation
move - transit time between work centers
scheduling techniques
forward scheduling
start when received order
may finish early
determine the earliest completion date
determine promise dates
builds inventory
backward scheduling
use MRP logic
schedule last operation to complete due date
schedule previous operations back from last operation
reduce inventory
infinity loading
assume that work center have capacity available
not consider existence of the competinf shop order
finite loading. there have a limit to available capacity
operation overlapping
next operation allowed to begin before the entire lot is complete
reduce manufacturing lead time
order, divided into at least 2 transfers lots
type of batches
process batch - lot size of product that has been released into production
transfer batch - lot size of product that move from work center to other work center
transfer batch - often less that process batch to aid in throyghput
cost involved
handling cost between work center
:arrow_up: queue wait for orders
idle time if 2nd batch not arrive in time
size of optimal transfer batch
operating splitting
reduces manufacturing lead time
order is split into at least 2 lots
similar machines are run simultaneously
setup time, low compared to run time
operators can run more machine
Load leveling
load report
tell PAC the current and upcoming load on work center
based on the standard hours operation for each order
scheduling bottleneck
some workstations are overloaded and some are underloaded
capacity is equal to or less that the demand put upon it
bottleneck control throughput
throughput (the total volume of product passing through a facility)
bottleneck principle
utilization of non-bottleneck resource is not determined by potential
using non-bottleneck 100% of time not produce 100% utilization
capacity facility depends on capacity of bottleneck
time saved at bottleneck does not save capacity elsewhere
capacity and priority must considered toghether
loads should be split
focus should be on balancing the flow in the shop
managing bottleneck
establish a time buffer before each bottleneck
control rate of material
provide the bottleneck with capacity
adjust loads
change schedule
back schedule before bottleneck - forward schedule after bottleneck
theory of constraints
identify the constraint
exploit the constraint
elevate the constraint
subordinate the constraint
once the constraint is no longer constraint, find new one and repeat the same step
Drum-buffer-rope
drum - pace of production set by the constraint
buffer - inventory established before the constraint to prevent it being "starved" of work
rope - coordinated the release material
cumulative variance
difference between total planned for a given period and the actual total for that period
cumulative variance = previous cumulative variance + actual - planned
operation sequencing
technique for short term planning of actual jobs to be run in each work center based on the capacities and priorities
dispatching
selecting & sequencing jobs to be run at work center
dispatch list
plant, department, work center
part number, shop order number, operation number adn description
standard hours
priority information
jobs coming to the work center
dispatching rule
FCFS (first come, first serves)
EDD (earliest job due date)
ODD (earliest operation due date)
SPT (shortest processing time)
CR - critical ratio
CR = (due date - present date) / lead time remaining
CR = actual time remaining / lead time remaining
CR<1 behind schedule
CR=1 on schedule
CR>1 ahead of schedule
CR<0 already late
production reporting
feedback of what is actually happen on the shop floor
needed for management
on-hand balance
on-order balance
job status
shortages
scrap
material shortages
report
order status
weekly input/output by department
exception reports
scrap
rework
late orders
inventory status
performance summaries
order status
work center efficiency
product tracking
lot traceability
tracking back to the origins
matching the colour
legislated in some industries
necessary for recalls
measurement system
evaluating performance to take corrective action
aligned with all performance measurement of organization
