# 13.3.1 The Manufacturing Calendar, or Shop Calendar

### Intended learning outcomes: Present characteristics of the manufacturing calendar, or shop calendar. Explain an example of a manufacturing calendar.

Measures of the load and capacity of a work center are often in units of time. In other cases as well, time quantities are necessary rather than load, at least for calculating lead time. It is a problem, however, that according to the Gregorian calendar, a week does not always contain the same number of (e.g., five) working days.

The manufacturing calendar or shop calendar counts working days only and omits nonworking days, such as vacations, holidays, or weekends.
The manufacturing date of the manufacturing calendar begins on day “zero,” which corresponds to a particular Gregorian date. For each working day, you add the value of one.

Figure 13.3.1.1 shows an excerpt from a manufacturing calendar.

Fig. 13.3.1.1       The manufacturing calendar.

A manufacturing calendar allows addition or subtraction of a certain number of working days to or from a given Gregorian date. Scheduling of orders often uses these calculations.

In addition, to gain the load profile of a work center when we want to compare the load over a particular time period with the capacity available, this calendar takes only working days into consideration.

## Course section 13.3: Subsections and their intended learning outcomes

• ##### 13.3 Scheduling of Orders and Scheduling Algorithms

Intended learning outcomes: Describe the manufacturing calendar and the calculation of the manufacturing lead time. Differentiate between Backward Scheduling and Forward Scheduling. Explain network planning, central point scheduling, the lead-time stretching factor, and probable scheduling. Present scheduling of process trains.

• ##### 13.3.1 The Manufacturing Calendar, or Shop Calendar

Intended learning outcomes: Present characteristics of the manufacturing calendar, or shop calendar. Explain an example of a manufacturing calendar.

Intended learning outcomes: Produce an overview on lead time scheduling. Identify definitions for the elements of operation time. Present the lead time formula and the start date as a function of completion date. Differentiate between manufacturing lead time, cycle time and throughput time.

• ##### 13.3.3 Backward Scheduling and Forward Scheduling

Intended learning outcomes: Produce an overview on lead time scheduling. Explain forward scheduling and backward scheduling. Describe a simple algorithm for backward scheduling.

• ##### 13.3.4 Network Planning and CPM — Critical Path Method

Intended learning outcomes: Explain network planning and the critical path method (CPM). Present an example of a scheduled network. Describe a network algorithm for backward scheduling.

• ##### 13.3.5 Central Point Scheduling

Intended learning outcomes: Explain central point scheduling. Describe several possible solutions in a directed network of operations.

• ##### 13.3.6 Probable Scheduling

Intended learning outcomes: Produce an overview on order urgency and slack time. Differentiate between forward, backward, and probable scheduling. Explain the role of the lead-time-stretching factor in probable scheduling.

• ##### 13.3.6b Calculating the Lead-Time-Stretching Factor

Intended learning outcomes: Describe the determination of the lead-time-stretching factor. Explain the equation for recalculation of lead-time-stretching factor.

• ##### 13.3.7 Scheduling Process Trains

Intended learning outcomes: Differentiate between reverse flow scheduling, forward flow scheduling, and mixed flow scheduling.