Aggregate Production Planning and Scheduling MCQ Quiz in বাংলা - Objective Question with Answer for Aggregate Production Planning and Scheduling - বিনামূল্যে ডাউনলোড করুন [PDF]

Explanation:

Gantt chart:

• Gantt charts are mainly used to allocate resources to activities.
• Gantt chart is applicable for Production scheduling.
• The resources allocated to activities include staff, hardware, and software. Gantt charts are useful for resource planning.
• A Gantt chart is a special type of bar chart where each bar represents an activity. 
• This chart lists the tasks to be performed on the vertical axis, and time intervals on the horizontal axis.
• The bars are drawn along a timeline. The length of each bar is proportional to the duration of time planned for the corresponding activity.
• With the use of this chart, we can check the progress of project with
  • A visual display of the whole project,
  • Timelines and deadlines of all tasks,
  • Relationships and dependencies between the various activities,
  • Project phases

On Gantt Chart one can easily view

• ​The start date of the project
• What the project tasks are
• Who is working on each task
• When tasks start and finish
• How long each task will take
• How tasks group together, overlap and link with each other
• The finish date of the project

Each activity is represented by a bar; the position and length of the bar reflect the start date, duration and end date of the activity. This allows you to see at a glance:

• What the various activities are
• When each activity begins and ends
• How long each activity is scheduled to last
• Where activities overlap with other activities, and by how much
• The start and end date of the whole project

Concept:

A production planning and control system has many functions to perform, some before the arrival of raw materials and tools, and others while the raw material undergoes processing.

There are four steps in the process of production planning and control:

Routing: Routing can be defined as the process of deciding the path (route) of work and the sequence of operations.

Scheduling: Scheduling function determines when an operation is to be performed, or when work is to be completed.

Dispatching: It is the action, doing or implementation stage. It comes after routing and scheduling. Dispatching means starting the process of production. It provides the necessary authority to start the work.

Expedition or follow-up: It is designed to keep track of the work effort. The aim is to ensure that what is intended and planned is being implemented. It maintains proper records of work, delays and bottleneck. Such records can be used in future to control production.

Forecasting is the technique that predicts the trend in future data with the help of the trend in historical data.

Explanation:

Material Requirement Planning (MRP):

• Materials requirements planning is a simple system of calculating arithmetically the requirements of the input materials at different points of time based on the actual production plan.

• MRP is a method of working out the production plan in a multi-stage production system that produces much product and requires their raw material and sub-assemblies. It is used so that all the things available at an appropriate time and production can be carried out without any delay.

• In the MRP system, the component demand is calculated from the Master production schedule.

• It can be seen from the figure that an MRP system has three major input components:

Master Production Schedule (MPS): 

• MPS is designed to meet the market demand (both the firm orders and forecasted demand) in the future in the taken planning horizon.
• MPS mainly depicts the detailed delivery schedule of the end products. However, orders for replacement components can also be included in it to make it more comprehensive.

Bill of Materials (BOM) File: 

• BOM represents the product structure. 
• It encompasses information about all subcomponents needed, their quantity, and their sequence of build-up in the end product. 
• Information about the work centres performing build-up operations is also included in it.

Job – shop production

• Job – shop production is characterized by the manufacturing of a large variety of products in small quantities that are designed and produced as per specifications are given by customers
• The main feature of this production system is that it is highly flexible
• A shop – shop comprises general-purpose machines arranged in different departments
• Example – Manufacture of aeroplanes and oil field equipment, machine tools, giant hydro turbine, rolling mills, and other heavy equipment

Batch production

• Batch production is a type of production in which the job passes through the functional departments in batches and each batch may have a different routing
• Batch production is characterized by the manufacture and stocking of a limited number of products at regular intervals, awaiting sales
• Example – Machine tools, pumps, compressors, stationary IC engines, etc.

Mass production

• In mass production, the same type of product is manufactured to meet the continuous demand of the product
• Manufacturing of discrete components or assemblies in a very large volume is called mass production
• Machines are arranged in a line according to the sequence of operations on the product
• Example – Nuts, bolts, screws, washers, pencils, matches, engine blocks, bicycles, electric motors, sewing machines, tractors, etc.

Concept:

The jobs will be sequenced using the Johnson rule and then the idle time will be calculated.

Steps:

• Find out the minimum of Ai and Bi.
• If the minimum is for a job on machine A then perform that job at the start.
• If the minimum is for a job on machine B then perform that job at the last.
• A job should be assigned only once.

Calculation:

Using the Johnson rule, sequence is:

We have the table:

Idle time = make span time – working time =

Idle time (Facing) = 43 – 42 = 1 min

Idle time (Threading) = 43 – 37 = 6 min

Concept:

• Gantt charts are mainly used to allocate resources to activities.
• The resources allocated to activities include staff, hardware, and software. Gantt charts are useful for resource planning.
• A Gantt chart is a special type of bar chart where each bar represents an activity. 
• This chart lists the tasks to be performed on the vertical axis, and time intervals on the horizontal axis.
• The bars are drawn along a timeline. The length of each bar is proportional to the duration of time planned for the corresponding activity.
• With the use of this chart, we can check the progress of project with
  • A visual display of the whole project,
  • Timelines and deadlines of all tasks,
  • Relationships and dependencies between the various activities,
  • Project phases

Features of product or line layout:

• Semi-skilled workers operate two or more machines.
• Highly specialized machines, jigs and fixtures are used.
• Conveyorized movement of inventories
• Small in-process inventory

According to Johnson’s algorithm sequencing of jobs is

Now,

From this the optimal make span of the shop is 115.

Concept:

A multi-product company means it will deal with a variety of products.

Batch production means the volume of production is not much high.

Layout planning in manufacturing and service organizations involves the physical arrangement of various resources available in the system to improve the performance of the operating system, thereby providing better customer services.

Layouts can be classified into the following four categories:

1. Process layout
2. Product layout
3. Group layout (Combination layout)
4. Fixed-position layout

Process layout:

• In a process layout, similar machines and services are located together; Therefore, all drills/lathe etc. will be in one area of the plant
• Process layout is normally used when the production volume is not much high as in product layout
• This layout is used because of the variety of products manufactured and their low production volume

Product layout:

• This type of layout is preferred where one type of product is produced and the product is standardized
• Product layout is used when machines and auxiliary services are located according to the processing sequence of the product
• The product layout is selected when the volume of production of a product is high such that a separate production line to manufacture it, can be justified

A group layout is a combination of the product layout and process layout. It combines the advantages of both layout systems.

Fixed-position layout:

In a fixed position layout, the service is performed around a customer that remains stationary while the work is being done.