Benefits of management by exception are as under :
(i) It saves the valuable time of the management.
(ii) It helps the management to identify important deviations which need timely action to keep the organization on the correct path.
(iii) It facilitates delegation of authority and helps in increasing morale of employees.
(iv) It helps the management to concentration on important matters beneficial for the long-term profitability of the organization.

It implies that manager must focus attention only on factors critical to performance. Normal factors or deviation should be ignored as they can be corrected at lower levels. It is based on the maxim – “and attempt to control everything results in nothing.
Based, on this, only major deviations from standards should be reported to top-level management and other routine problems should be looked into by the subordinates.
For example, if a plan allows 5 percent decrease in the output as acceptable range of deviation then only such decrease in output should be reported to the management as 1’s well beyond 5 percent.

The given statement – “Control does not require any process” is not correct. Process of management control involves the following steps.
Setting performance Standard : Standards are required to judge whether the actual performance is proceeding in the right way. Standards must be in numerical or measurable terms.
Measurement of Actual performance : Actual performance is evaluated and expressed in terms of planned standards.
Comparing Actual performance with standards : Actual performance is compared with the planned performance and deviations if any found out.
Analysing the deviations : In order to know the causes of deviations, and in order to take corrective actions, deviations are analysed.
Taking corrective Actions : If the deviations exceed the acceptable limits they should be immediately brought to the notice of management for taking corrective measures. Thus it is clear that controlling requires systematic process.

Controlling should not be misunderstood as the last function of management. It is a function that brings the management cycle back to the planning function.

In general, the process of management begins with planning and ends at controlling, but when a manager performs the function or steps of controlling, it is observed that the first step of controlling is planning standards. The controlling function finds out how far actual performance deviates from the standards and analyses the corrective actions to be taken.

This process helps in formulating of future plans, thus becomes the premise of setting plans. Therefore, we can say it is the beginning of management process. Thus, it can be stated that, controlling function is both the beginning as well as the end of the management process.

Controlling ensures that the activities in an organization are performed as per plans.
Importance of controlling can be highlighted by the following points:
(i) It helps in achieving the organizational goals.
(ii) It helps in judging the accuracy of standards.
(iii) It facilitates efficient use of resources.
(iv) It provides direction to all activities and thus, it facilitates coordination.

Planning and controlling are interrelated and interdependent
Planning is the base of controlling function, as controlling involves measurement of performance against the standards to analyze deviations and take corrective action. Thus, controlling is impossible without planning.
Planning without controlling is meaningless because, in the absence of controlling, it is impossible to minor the progress and keep a check on the proper implementation of plans. Thus, without controlling, planning will fail to achieve objectives.
Planning is a thinking process while controlling is an executive function. While planning involves creative thinking, imagination and sound judgment, controlling ensures that such decisions are converted into desired actions. Thus, planning is prescriptive, whereas, controlling is evaluative.
On the basis of the above discussion, it is concluded that planning and controlling are interrelated and reinforce each other because:
(i) Planning based on facts makes controlling easier and effective.
(ii) Controlling improves future planning by providing information derived from past experiences. 
Both are Forward-looking as well as Backward-looking Functions
1. Planning is a Forward-looking Function
Planning involves setting objectives and deciding the future course of action to achieve them. Thus, it is regarded as a forward-looking function.
2. Controlling is a Backward-looking Function
Controlling involves a post-mortem of the past activities of an enterprise and finding out deviations from the targeted standard. Thus, it is regarded as a backward-looking function.
3. Planning is a Backward-looking Function
Planning is guided by the past experiences and corrective actions taken in the controlling process. Thus, it is regarded as a backward-looking function.
4. Controlling is a Forward-looking Function
The process of control necessarily involves analyzing deviations and taking corrective action, which aims to improve future performance and achievement of predetermined goals. Thus, it is regarded as a forward-looking function.

Planning and controlling are interrelated and interdependent
Planning is the base of controlling function, as controlling involves measurement of performance against the standards to analyze deviations and take corrective action. Thus, controlling is impossible without planning.
Planning without controlling is meaningless because, in the absence of controlling, it is impossible to minor the progress and keep a check on the proper implementation of plans. Thus, without controlling, planning will fail to achieve objectives.
Planning is a thinking process while controlling is an executive function. While planning involves creative thinking, imagination and sound judgment, controlling ensures that such decisions are converted into desired actions. Thus, planning is prescriptive, whereas, controlling is evaluative.
On the basis of the above discussion, it is concluded that planning and controlling are interrelated and reinforce each other because:
(i) Planning based on facts makes controlling easier and effective.
(ii) Controlling improves future planning by providing information derived from past experiences. 
Both are Forward-looking as well as Backward-looking Functions
1. Planning is a Forward-looking Function
Planning involves setting objectives and deciding the future course of action to achieve them. Thus, it is regarded as a forward-looking function.
2. Controlling is a Backward-looking Function
Controlling involves a post-mortem of the past activities of an enterprise and finding out deviations from the targeted standard. Thus, it is regarded as a backward-looking function.
3. Planning is a Backward-looking Function
Planning is guided by the past experiences and corrective actions taken in the controlling process. Thus, it is regarded as a backward-looking function.
4. Controlling is a Forward-looking Function
The process of control necessarily involves analyzing deviations and taking corrective action, which aims to improve future performance and achievement of predetermined goals. Thus, it is regarded as a forward-looking function.

Planning is the basis for control in the sense that it provides the entire spectrum on which control function is based. In fact, these two terms are often used together in the designation of the department which carries production, planning and scheduling. Control measures the behaviour and activities in the organisation and suggests measures to remove deviations, if any.
Control is the result of particular plans, goals or policies. Thus, planning offers and affects control. Also,planning is affected by control in the sense that much of the information provided by control is used for planning. Thus, there is a reciprocal relationship between planning and controlling.