work schedule

The work plan ( English route sheet) or production plan is an essential tool in workplace-oriented production , for example in mechanical engineering and electrical engineering .

Production plan and work plan can also be differentiated: The production plan is an operationally prescribed plan according to which a work or production process must be carried out absolutely. A work plan is an individually created plan that is created by the skilled worker / trainee. The basis is the technical drawing. It is created in the work planning organizational unit and defines the work processes and their sequence for manufacturing a single part , an assembly or a finished product .

A work plan describes the flow of a product from the raw material through various work processes and production facilities to the finished product. For each work process, the details of the activities in the machine facilities are specified and often supplemented with further organizational information, such as the estimated set-up times , unit times , the production cost centers and production facilities . It also names the work equipment and material to be used, such as measuring equipment , devices and special tools .

In contrast to the parts list , which documents what a new part is made of (as a general term for individual part, assembly and product), the work plan documents the work steps for manufacturing the product. The work plan and parts list are linked in the sense that for each work process in the work plan, reference is made to the quantity of raw materials , semi-finished products or assemblies required and their possible parts list specifications.

Use of a work plan

A work plan, together with a drawing and parts list, forms the basis for production planning and control . In particular, it is an important tool for

• the creation of work documents and process-controlled document postings (work papers, wage documents, material withdrawal and confirmation documents)
• the scheduling and capacity planning
• the production and assembly processing
• the pre- and post-calculation of the finished products
• the remuneration in the case of piecework wages .

Determination of the production time

For the production controlling the routing allows the process per predetermined cycle times the determination of the production time by the cycle times of the individual manufacturing processes are multiplied by the batch size Quantity:

${\displaystyle {\text{Standard-Fertigungszeit}}=\sum _{k=1}^{N}\left(\mathrm {R{\ddot {u}}stzeit} [k]+\mathrm {Losgr{\ddot {o}}ssenmenge} \cdot \mathrm {St{\ddot {u}}ckzeit} [k]\right)}$

with a work plan with N operations and

Part time [ k ]: Part time of work process [ k ]

Setup time [ k ]: Setup time of work process [ k ]

The set-up times for the work processes only occur once per production lot. In actual cost accounting, the actual production costs can be determined based on the production times and offset from the cost centers to the cost units. As part of the production program planning, the work plans enable the determination of planned production times and thus a planning and optimization of the capacity utilization of the individual production points. There can be several work plans with different lot sizes per product, which can be used to summarize secondary requirements in the order calculation of high-quality A-parts.

If there are currently maintained work plans, an ERP system can automatically determine the standard production time by means of retrograde consumption calculation. These retrograde calculations and resulting cost postings can e.g. B. be triggered by the warehouse receipt notification of the finished or semi-finished products.

Determination of the production costs

The production costs can be determined in the same way:

${\displaystyle {\text{Standard-Fertigungskosten}}=\sum _{k=1}^{N}\left((\mathrm {R{\ddot {u}}stzeit} [k]+\mathrm {Losgr{\ddot {o}}ssenmenge} \cdot \mathrm {St{\ddot {u}}ckzeit} [k])\cdot {\text{Kostensatz}}[k]\right)}$

With

Cost rate [ k ]: Cost rate for the working time of the cost center on which the work process [ k ] is carried out [GE / time]

Creation and maintenance of work plans

Work plans are often prepared in the work preparation of a specialized department, which is in close contact with the production , manufacturing , assembly and development departments, depending on the task .

Content of a work plan

In the work plan header , the heading , there is both what is to be manufactured (identification of the part to be manufactured, drawing number, sketch) and what it is to be created from (material, raw material, dimensions). In the lines of the work plan, the work processes , it is stated how (e.g. sawing, turning, milling), where (at which workplaces ) and with what (tools) this should happen and how long (what time period is planned for the processes) .

A work plan consists of 1: n work processes that usually have to be processed one after the other. Often, however, special cases due to technology also arise, such as the division of the sequence of operations into parallel operation sequences and subsequent merging of the parts for joint finishing. A work plan can therefore usually be viewed as a simple network plan .

In contrast to the production plan, the work plan is workplace-related. Protective provisions for employees must therefore be observed and included in the work plan. This applies in particular to the provisions of the Occupational Safety and Health Act . This includes a risk assessment , the planning of measures to avert danger and the planning of the effectiveness check of the measures. In companies with a works council , work planning itself is not subject to co-determination, but the works council is obliged to monitor that protective provisions are implemented during work planning and that this is documented accordingly.

Work plan types

The degree of detail of the work plans depends on the type of production , whether individual production or small series, series or mass production . Series production requires a higher level of detail than individual production.

Standard work plans are standardized templates for the production of similar parts or similar processes (e.g. test work plans). Alternate routings contain alternate operations (using alternate machines) or alternate sequences of operations. There are different work plans for a part for use with different batch sizes to be produced . Variant work plans are used in production with many variants .