Wednesday, January 23, 2008

Manufacturing Management

Manufacturing Management

The Environment:

Types of Companies:

  • Basic producer (Manufacturer)
  • Converter (Process)
  • Fabricator

Methods of Production:

  • Job Shop (Project based)
  • Assembly Line
    • Batch production
    • Mass production (Continuous Production)
  • Combination of above

Types of planning:

  • Buy from outside
  • Make within the company
    • Make to stock (Manufacture in advance to compensate demand)
    • Make to order (Manufacture as and when order comes)
    • Make to assemble (Manufacture spares for assembly)
    • Assemble to order (Assemble as and when order comes)

Concerns of Manufacturing Organization:

Costly Business:

  • Material Cost- Investment in inventory
    • Direct Material Cost
    • Indirect Material Cost
  • Cost of Machines – Machine Utilization
  • Manpower cost – Operator efficiency
    • Direct labor cost
    • Indirect labor cost

A complex & Changing Product:

  • Product enhancement – New technology, new material
  • Engineering change control

A Competitive Business:

  • Customer expects quality product at reasonable cost
  • Less time to market
  • Changing pattern of demand
  • Less time for delivery

A changing environment:

  • Pains of growth or recession
  • Complexity in planning and scheduling of resources

Decentralized Production Planning:

  • Problem in reconciling the requirement of sales
  • Production and the financial interests.

An Information Explosion:

  • Gathering and dissemination of information I the most difficult problem as information is voluminous, scattered & difficult to obtain.

Functions of manufacturing Management:

  • Preparation of Master Production Plan
  • Preparation of Master Production Schedule (MPS)
  • Capacity Requirement Planning (CRP)
  • Material Requirement Planning (MRP)
  • Production Planning
  • Shop Floor Control

Master Production Plan:

Objective:

  • To achieve the budgeted turnover
  • Optimum utilization of resources
  • Smooth production process

Product-wise requirement during various periods

  • Long range plan
  • Short range plan

Inputs for Preparing Master Production Plan

  • Order booking
  • Demand forecast (Products, spares, etc.)

Demand Forecast

  • Factors influencing demand forecast:
    • Life cycle of product
    • Product phase
    • Number f products
  • Forecast can be based on:
    • Past data patters (future projection)
    • Economic trends
    • Competition
    • Market trend

Master Production Schedule:

Objective:

  • To provide feasible master schedule for production
  • To provide basis for decision-making regarding
    • Specific production dates
    • Available capacity
    • Total demand
    • Lead time
    • Inventory constraints
  • The MPS is stated in terms of specific products that are to be produced in certain quantities by certain dates
  • MPS specifies:
    • Sizing and timing of production order for specific items
    • The sequencing of individual jobs
    • Allocation of resources to individual activities & operation.

Capacity Resource Planning (CRP):

Objective:

  • To determine long-term & short term capacity needs.
  • To mach the resources to demand
  • To determine the acquisition of required resources

Long term capacity strategies:

  • Following changes will revise he demand resource requirements:
    • Development of new product lines
    • Expansion of existing facilities
    • Construction or phasing out of production plant
  • Acquiring of resources
  • Make or buy decision

Short term capacity strategies:

  • Capacity planning for the short period to take care of fluctuation in demand during short term due to
    • Seasonal factor
    • Economic factor
  • Following strategies can be used to cope up with fluctuation in demand
    • Extra shift working, overtime
    • Sub-contracting
    • Hiring or firing of people
    • Purchasing instead of manufacturing

Capacity planning:

  • Capacity is the rate of output that can be expected from a given entity. It is the highest sustainable rate of output which can be achieved with current production mix, worker effort, plan and equipments (hrs, qty, etc…)
  • Load is the total quantity or volume required to be processed through a given entity.
  • Capacity management is the planning and control function which is link between the production plan and manufacturing resources.
  • Rough-cut Capacity planning is the process of converting the production plan and/or the MPS into capacity need for the key resources.

Advantage of Capacity planning (CRP):

  • Helps to simulate proposed production plan
  • Helps to rescheduling the production plan to balance workload
  • Identifies end-item to be rescheduled
  • Identify rescheduled effects on all work-centers
  • Reduces idle time and queue time.
  • Reduce work-in-process (WIP) inventory
  • More efficient use of machines and people

Material Requirement Planning (MRP)

MRP is a planning tool designed to provide visibility into the future to predict potential challenges. MRP is the best re-planning tool available because through the use of the speed of computer, it can re-plan and adjust priorities based on changes in the original plan.

Objective

  • Inventory reduction
    • No excess inventory
    • No mismatch inventory
    • No non-moving or dead stock
  • To ensure availability of required material
    • In right quantities
    • At right time
    • At right place
  • To enhance customer satisfaction by realistic commitment
  • To increase production efficiency
    • Reduction in idle time, queue time
    • Increase production capacity by better co-ordination among work-centers
  • To help in providing faster response to changing condition
    • Material shortages
    • Machine breakdowns
  • By forward planning, help supplier to reduce lead time and minimize production and inventory carrying cost.
  • To help arrive at accurate cost of production.

MRP process:

  • It relates the dependent requirements for the material and components comprising in end product to time periods know as “buckets” over a planned horizon on the basis of Master production Schedule (MPS)
  • It is used to determine how much of each material needs to be purchase or item to be manufactured in the planning horizon to ensure that orders are fulfilled on time
  • To accomplish this task MRP uses:
    • Master production Schedule (MPS)
    • Bill of material (BOM)
    • On-hand quantity (Available stock)

· MRP provides requirement oriented operations for manufacturing parts and/or assemblies for the final product, which are very important to manufacturing firms.

Steps involved in MRP:

  • Compute Gross requirement of dependent items based on MPS
  • Add requirement of independent items to gross requirement (e.g. requirement of spare parts)
  • Compute Net requirement of items by netting the gross requirement with that of Lead time
  • Determine the Production lot
  • Offset the production lots for lead time
  • Separate out requirements of Purchased items and Manufactured item
  • To calculate Cumulative Net Requirement use BOM
    • Define product / Assembly / Component structure
    • Parent-Child relationship
    • Quantity of Child required per Parent
    • Also define stage in assembly where the item is required.
    • Creation of BOM
      • New
      • From Existing structure
    • Explosion or Implosion of BOM

Production Planning:

  • Production planning is the pre-determination of manufacturing resources such as material, machine, manpower, minutes & money for the production of good of the right quality, in right quantity and at the right time.
  • It is the determination, acquisition and arrangement of all facilities necessary for future production of items.

Functions of Production Planning:

  • Shop scheduling (Machine loading chart)
  • Material Control (Material Requisition Note)
  • Process Planning & Routing (Route Card, Process Sheet)
  • Follow up of WIP

Shop Floor Control:

Objective:

  • To control day-to-day production activity to achieve production targets.
  • Work measurement (Efficiency & Productivity)
  • Reduce Work-in-Process
  • Improve utilization of production resources
  • Collect cost, quality and maintenance related data.

Functions:

Work Order Management:

  • Release of Work Order or Mfg, order
    • Work order
    • Material requisition note
    • Route card
    • Time ticket
    • Move ticket
    • Inspection order
    • Process sheet
  • To get required material & tools issued from stores
  • To move material between two work-centers
  • Stage inspection
  • Prepare Material Rejection Note for rejected material
  • Prepare Material Delivery Note for finished material

Work-in –Process Management:

  • Tracking of W/O based in routing information
  • Work Measurement
    • With respect to labor efficiency
    • With respect to productivity
  • Yield reporting
  • Rejection control
  • Monitoring of returns from shop

Information Reports:

  • Shift-wise labor efficiency
  • Shift-wise production completion details
  • List of completed Work Orders during the period
  • List of pending Work Orders as on date
    • Work order wise
    • Finished item-wise
  • Machine utilization for the period
  • Down time analysis
  • Analysis of rejections
    • Due to process
    • Due to operator
  • Report of scrap generated
  • Material Consumption analysis