Pattern flow and activity relationship

Pattern flow and activity relationship

In determining the requirements of a facility, three important considerations are flow, space, and activity relationships.

• Flow depends on lot sizes, unit load sizes, material handling equipment and strategies, layout arrangement, and building configuration.

• Space is a function of lot sizes, storage system, production equipment type and size, layout arrangement, building configuration, housekeeping and organization policies, material handling equipment, and office, cafeteria, and restroom design.

• Activity relationships are defined by material or personnel flow, environmental considerations, organizational structure, continuous improvement methodology

Activity Relationship

Activity relationships provide the basis for many decisions in the facilities planning process. The primary relationships are considered are

1. Organizational relationships, influenced by a span of control and reporting relationships.

2. Flow relationships, including the flow of materials, people equipment, information, and money.

3. Control relationships, including centralized versus decentralized materials control, real time versus batch inventory control, shop floor control, and levels of automation and integration.

4. Environmental relationships, including safety considerations and temperature, noise, fumes, humidity, and dust.

5. Process relationships other than those considered above, such as floor loading, requirements for water treatment, chemical processing, and special services.

Several relationships can be expressed quantitatively; others must be expressed qualitatively. Flow relationships are typically expressed in terms of the number of moves per hour, the quantity of goods to be moved per shift, the turnover rate for inventory, the number of documents processed per month, and the monthly expenditures for labor and materials.

A flow process may be described in terms of the subject of flow, the resources that bring about the flow, and the communications that coordinate the resources.

The subject is the item to be processed. The resources that bring about flow are the processing and transportation facilities required to accomplish the required flow. The communications that coordinate the resources include the procedures that facilitate the management of the flow process.

If the flow process being considered is the flow of materials into a manufacturing facility, the flow process is typically referred to as a materials management system. The subjects of material management systems are the materials, parts, and supplies purchased by a firm and required for the production of its product. The resources of material management systems include:

1. The production control and purchasing functions

2. The vendors

3. The transportation and material handling equipment required to move the materials, parts, and supplies

4. The receiving, storage, and accounting functions

If the flow of materials, parts, and supplies within a manufacturing facility is to be the subject of the flow process, the process is called the material flow system. The type of material flow system is determined by the makeup of the activities or planning departments among which materials flow. There are four types of production planning departments (figure 1):

1. Production line departments

2. Fixed material location departments

3. Product family departments

4. Process departments

The material flow systems for each department type are shown in fig The subjects of material flow systems are the materials, parts, and supplies used by a firm in manufacturing its products. The resources of material flow systems include:

1. The production control and quality control departments

2. The manufacturing, assembly, and storage departments

3. The material handling equipment required to move materials, parts, and supplies.

4. The warehouse.

If the flow of products from a manufacturing facility is to be the subject of the flow, the flow process is referred to as the physical distribution system. The subject of physical distribution systems are the finished goods produced by a firm. The resources of physical distribution systems include:

1. The customer

2. The sales and accounting departments and warehouses

3. The material handling and transportation equipment required to move the finished product

4. The distributors of the finished products.

Flow Patterns

Patterns of flow may be viewed from the perspective of flow within workstations, within departments, and between departments.

Flow within Workstations

Motion studies and ergonomics considerations are important in establishing the flow within workstations. For example, flow within a workstation should be simultaneous, symmetrical, natural, rhythmical, and habitual.

Flow Within Departments

The flow pattern within departments is dependent on the type of department. In a product and/or product family department, the flow of work follows the product flow.

End-to-end, back-to-back, and odd-angle flow patterns are indicative of product departments where one operator works at each workstation. Front-to-front flow patterns are used when one operator works on two workstations and circular flow patterns are used when one operator works on more than two workstations.

In a process department, little flow should occur between workstations within departments. Flow typically occurs between workstations and aisles. Flow patterns are dictated by the orientation of the workstations to the aisles.

Diagonal flow patterns are typically used in conjunction with one-way aisles. Aisles that support diagonal flow pattern often require less space than aisles with either parallel or perpendicular workstation-aisle arrangements. However, one-way aisles also result in less flexibility. Therefore, diagonal flow patterns are not utilized often.

Flow between Departments

An important consideration in combining the flow patterns shown in figure 5.14 is the location of the entrance and exit. As a result of the plot plan or building construction, the location of the entrance (receiving department) and exit (shipping department) is often fixed at a given location and flow within the facility conform to these restrictions. A few examples of how flow within a facility may be planned to conform to entrance and exit restrictions are given in figure.