German national coach Julian Nagelsmann is not participating the European Championship with only 11 players. He takes 26. This allows him to tactically adjust the line-up to the opposing team. And he knows that players can drop out; through injuries, through suspensions. When Germany plays against Scotland on June 14^th only 11 German players will be in action at the same time. The other 15 are Nagelsmann’s reserve.

What seems logical in soccer is not always obvious in other industries. In public transport for example, at airports or in operating theaters. Cancellations of trains, flights, and operations are the consequences. The reason: a shortage of manpower. Something went wrong when planning the reserve.

It is a phenomenon of our time that insufficient buffers are planned in the schedule. For years, workforce management meant planning as demand-oriented as possible. However, many companies have overstepped the mark. Cost optimization leads to problems in other areas: the quality of service decreases if too few personnel reserves are planned. Even small schedule deviations can have huge effects. 

Planning a realistic reserve is a measure that all companies can infer from the experience of previous years. Absences due to illness cannot usually be foreseen and taking average values into account in planning only helps to a limited extent. The sickness rate hardly ever corresponds to the annual average. Vacation, however, can be planned. It is, therefore, all the more surprising that so many companies fail to create a sensible reserve plan for the holiday season. Without a reserve, scheduling is only possible for those who do not have to carry out time-critical work or can compensate for the loss with remaining employees. This is not the case for public transport, aviation and operating theaters. In aviation in particular, the need for employees increases precisely when a large number of employees want to take vacation. A dilemma. But one that can be prepared for.

A scheduler must determine the working time required in good time, calculate how much leave can be granted in which periods, and compare leave entitlements with the employees’ holiday wishes. But even if the team line-up is perfect in this sense, the goalkeeper can drop out due to a foot injury. It is particularly important, especially when the staffing cover is thin, that the scheduler plans for “substitutes”.

But who are these “substitutes” in scheduling and where do they come from? There are various approaches to planning a reserve. One option is to acquire help from other areas or to recruit temporary workers. Another would be to set up a group of relief employees, create reserve shifts, flex shifts or on-call services. A combination of reserve planning scenarios can also be useful. Working time accounts can help to improve dynamic requirements cushioning. In this way, overtime incurred during the holiday season or as a result of employee absenteeism can be offset in times of low demand.

In order to allocate shifts as fairly as possible, especially during the popular holiday periods, to observe all working time rules and to be able to react to changes at short notice, all information must be clearly compiled. An overview of each employee’s leave account status prevents unpleasant surprises, for example, due to remaining leave entitlements at the end of the year. It must be easy to see how many employees, with which qualifications, are on vacation and when, in order to be able to determine in good time when understaffing might occur. Only then can the planner keep control of the schedule. Nagelsmann can only continue to adapt his strategy by using reserve planning.

A stable schedule requires reliable reserve planning. Only then does it run smoothly, within a company and on the pitch. If Jogi Löw were only to take 11 players to the World Cup, he wouldn’t be the national coach for long. Check your reserve planning now – the outcome could depend on it.