CHAPTER 12
Objectives
AGGREGATE PLANNING
1. What is aggregate planning? In production
planning, it is the intermediate-range capacity planning that typically covers
a time horizon of 2 to 12 months.
- What is the purpose of aggregate planning? The
purpose of aggregate planning is planning ahead because it takes time to
implement plans. The second reason is strategic of the company and third
aggregate planning help synchronize flow throughout the supply chain; it
affects costs, equipment utilization, employment levels and customer
satisfaction.
- List
the demand options in aggregate planning?
1. Price
2. Promotion
3. Back orders
4. New demand
4. List the capacity
options in aggregate planning
1. Hire and lay off workers
2. Overtime/slack time
3 part-time workers
4. Inventories
5. Subcontracting
5. List the main
strategies for meeting uneven demand.
1. Maintain a level of workforce
2. Maintain a steady output rate
3. Match demand period by period
4. Use a combination of decision variables
6. Name two important
factors that influence choice of strategy.
They are company policy, which may set constraints on the available options
the extent to which they can be used and cost also influence choice strategy.
- Briefly
describe the informal, trial and error approach to aggregate planning.
Trial-and-error approach of planning consist of developing simple tables
or graphs that enable planners to visually compare projected demand
requirements with existing capacity.
- What difficulties do services pose for aggregate
planning?
1. Services occur when they are rendered-most services can’t be
inventories and services capacity that goes unused is wasted.
2. Demand for services can be difficult to predict. There is a greater
burden for service providers to anticipate demand; therefore they have to
pay careful attention to planned capacity levels.
3. Capacity availability can be difficult to predict. In services, the
types of variety of task are more pervasive than compare with manufacturer
and this makes it difficult to establish measures of capacity.
- Explain these terms:
Disaggregating the aggregate plan- this means breaking down the
aggregate plan into specific product requirements in order to determine
labor requirement (skills, size, or workforce), materials, and inventory
requirements.
Master schedule- the result of disaggregating the aggregate plan is
master schedule showing the quantity and timing of specific end items for
a scheduled horizon that covers about six to eight weeks ahead.
Rough-cut capacity planning-this involves testing the feasibility
of a proposed master schedule relative to available capacities, to assure
that no obvious capacity constraints exist. It means checking capacities
of production and warehouse facilities, labor, and vendors to ensure that
no gross deficiencies exist that will render the master schedule
unworkable.
ATP or Available to Promise inventory- the master schedule process
uses this information on a period-by-period basis to determine the
projected inventory, production requirements and the resulting uncommitted
inventory.
- Why is it important to stabilize the master
schedule?
Master schedule enables marketing to make valid delivery, enables
production to evaluate capacity requirements, and provides necessary
information for production, marketing and senior management with
opportunity to determine whether the business plan and its strategic
objectives will be achieved.
- How are master schedules stabilized?
By the master scheduling process which involves the input and outputs.
- The duties of the master scheduler generally
include:
1. evaluating the impact of new orders.
2. Providing delivery dates for orders.
3. Dealing with problems:
a. evaluating the impact of production delays or
late deliveries of purchased
goods.
b. Revising the master schedule when necessary because of
insufficient
supplies of capacity.
c. Bringing instances of insufficient capacity to the attention of
production and marketing personnel so that they can participate in
resolving conflicts.
- List the inputs and outputs of master scheduling:
Inputs- the beginning inventories, which is actual quantity on hand from
the preceding period; the forecasts for each period of the schedule; and
the customer orders, which are quantities already committed to customers.
Outputs- Projected inventory, master production schedule and uncommitted
inventory.
- What are time fences?
Are use to facilitate order promising and the entry of orders into the
system? It divides a scheduling time horizon into three phases, frozen,
slushy and liquid.
Briefly describe these
scheduling phases:
Frozen-is the near term-phases that is so soon that delivery of a new
order would be impossible, or only possible using very costly or extraordinary
options such as delaying another order.
Slushy- is the second phase, and its time fence is usually a few periods
beyond the frozen phase.|
Liquid-is the farthest out on the time horizon.