1. Introduction
In the actual production scheduling process, it is often overlooked that the processing time of a job increases with the wear and tear of the machine. The scheduling in which the processing time of a job is an increasing function of its starting time, which is called deterioration effect (time-dependent) scheduling, represented by
(Yin et al. [
1], Sun and Geng [
2], Gawiejnowicz [
3], Miao et al. [
4], Sun et al. [
5]). Zhao and Hsu [
6] studied the problem of minimizing the number of weighted tardy jobs in a single machine using a general linear deterioration model. They proposed a fully polynomial-time approximation scheme to solve the problem. Li et al. [
7] discussed online batch scheduling with simple linear deterioration. For the makespan minimization, they proposed the best online algorithms for incompatible families. Chen and Yuan [
8] also proposed two unified methods for general linear deterioration models in environments with deadlines. Liang et al. [
9] considered single-machine scheduling with the linear combination of the convex resource allocation and deterioration effect. For the total completion time minimization, they proposed a heuristic and a branch-and-bound for solving the group scheduling problem. Cheng et al. [
10] explored single-machine scheduling with step-deteriorating jobs. For the total completion time minimization, they developed a polynomial-time algorithm for this NP-hard problem. And, Pei et al. [
11] provided a review of the application of deterioration effects in practical production in recent years.
In addition, the due window assignments will be established based on customer requirements (Janiak et al. [
12]). There are generally three kinds of due windows, one of which is a common due window (denoted as
), that is, the
is shared by all jobs and can be recorded as
, where
(resp.
) represents the starting (resp. finishing) time of the due window. The second one is the slack due window (denoted by
), where the due window of job
can be denoted as
, where
and
are the decision variables, and
is the processing time of job
. The third one is a different due window (denoted by
) for each job, which can be represented as
, where
(resp.
) represents the starting (resp. finishing) time of the due window for job
, whilst
and
are the decision variables. If a job is completed before
, it incurs an earliness cost; if completed after
, there will be a tardiness cost; if a job is completed within the interval
, no additional costs will be incurred. Among them, Huang et al. [
13] and Xu et al. [
14] considered single-machine scheduling with the
. Shabtay et al. [
15] proposed a pseudo-polynomial-time algorithm for the NP-hard problem of a common due window assignment with a bounded location. Shabtay et al. [
15] proposed a pseudo-polynomial-time algorithm for the common due window assignment problem with a bounded location. Zhao [
16] investigated the two-machine flowshop scheduling with both the
and resource allocation. For the three versions of scheduling cost and resource consumption cost, they proved that the problem can be solved in polynomial time. Jia et al. [
17] discussed the combination of the
and deterioration effects. Lv and Wang [
18] researched the two-machine flowshop scheduling with the
and resource allocation. Lin [
19] worked on single-machine scheduling with the
,
and
. Under position-dependent weights, learning and deterioration effects, they demonstrated that some problems are polynomially solvable. Teng et al. [
20] investigated single-machine scheduling with deterioration effects under the
and
.
Besides the due window, there is another important factor to consider in scheduling problems, namely the past-sequence-dependent delivery time (denoted as
, as can be seen in Koulamas and Kyparisis [
21]). Toksari et al. [
22] and Ren et al. [
23] examined the scheduling problems with an exponential
and learning effects. Qian and Han [
24] studied the single-machine problem with simple linear deterioration and
. Under three due date assignments, they proposed a polynomial time algorithm to solve the problem, respectively. Recently, Qian and Zhan [
25] integrated two types of due windows (i.e.,
and
), deterioration effects and
. They proposed polynomial-time algorithms for minimizing total weighted earliness, tardiness, starting time, and size of due window, where the weights of all jobs (corresponding to earliness, tardiness, starting time and size of due window) are equal. Pan et al. [
26] considered the single-machine scheduling with deterioration effects and
. Under the common, slack, different due dates and position-dependent weights, they proved that the problem can be solved in polynomial time.
Based on the above description, in order to investigate the deterioration effects and past-sequence-dependent delivery time on the job processing under the conditions of the specified due windows, then building upon the work of Qian and Zhan [
25] and Pan et al. [
26], this paper minimizes the weighted sum of earliness, tardiness, starting time, and the size of due window, where the weights are position-dependent coefficients (i.e., the weight is not related to the job but to the position, as can be seen in Sun et al. [
5] and Liu et al. [
27]), i.e., the work of Qian and Zhan [
25] and Pan et al. [
26] is a special case of this paper. After theoretical analysis, the positions of two jobs can be determined by comparing the difference between them (see
Section 3 and
Section 4 in details), and this method can be solved in a simple polynomial time with a complexity of
, where
N is the number of jobs. The structure of this paper is as follows:
Section 2 describes the problem;
Section 3,
Section 4 and
Section 5 provide specific algorithms for solving the three kinds of due windows.
Section 6 gives a numerical example.
Section 7 presents the conclusion.
The aforementioned literature and the specific problems studied in this paper are given in the following table (
Table 1).
2. Problem Definition
This problem can be described as follows:
N jobs (represented by the set
) are processed through a single-machine, and all jobs starting from
(
). The starting time and finishing time of the
can be represented by the interval
, and
is the size of a common due window. Let
be the
kth position, the earliness and tardiness are denoted by
and
, respectively, where
is the completion time of job
. For the interval of
, it can be expressed as
with the due window size is
. The earliness and tardiness in this case are
and
, where
,
,
, and
are all decision variables; for
, the interval is
and the size of the due window
is
. The problems under
,
, and
due to window conditions can be described as follows:
and
where
,
,
, and
(
) are position-dependent weights. The actual processing time
of job
(which is scheduled at the
k-th position in a sequence) can be expressed as:
where
(respectively,
) is deterioration rate (respectively, starting time) of
. In addition, the past-sequence-dependent delivery time (
) of
is:
where
is a delivery rate, and
with
. The corresponding completion time
is:
3. Solution of CONDW
In order to solve , the following optimal properties are given.
Lemma 1. For any given job sequence, the optimal and are equal to the completion times of two certain jobs.
Proof. Case I. When
and
with
,
, and the objective is
For
, the objective function is:
For
, we have
If , ; otherwise .
Case II. When
and
with
, we have
For
, we have
For
, we have
If , ; otherwise .
Case III. When and , in which , it is considered the general case. When moves left or right so that , it becomes Case II; when moves left or right, so that , it becomes Case I. □
Lemma 2. For the optimal sequence of jobs, and , where v satisfies and ; and u satisfies and .
Proof. When
and
, the objective function can be expressed as
Case I. When
moves
units to the left and
, the objective function becomes
that is,
.
When
moves
units to the right with
, the objective function is
namely,
.
Case II. When
and
moves
units to the left, such that the objective function is
that is,
.
When
and
moves
units to the right, and the objective function is
namely
. □
Based on the above lemmas, it can be assumed that, in a given optimal sequence, and . Define the sets , , , , and , where is the sequence of jobs.
Lemma 3. In the optimal sequence, the jobs in are sorted in descending order of .
Proof. Let
and
, respectively, be in the
x-th and
-th positions in
; thus, the sequence can be written as
, and the sequence
is obtained by exchanging the two jobs. Then, the subtraction of the objective function
F corresponding to the sequence
and
corresponding to
is
Note that is constant, and if , then . □
Lemma 4. The deterioration rates of the jobs in are lower than those of any job in .
Proof. Assuming that
and
are at the
v-th and
-th positions, and the sequences before and after exchange are
and
. The difference between the objective functions of the two is
It follows from Lemma 2 that
v satisfies the inequality
, then the term
can be obtained. To make
, there is
. □
Lemma 5. For the jobs in , the optimal sequence is sorted according to any ordering of .
Proof. and are the jobs at the x-th and -th positions in , in which . Let and be the sequences before and after the exchange, respectively. Since and do not change, there is . □
Lemma 6. The deterioration rates of any job in are less than those in .
Proof. is in the
x-th position, where
, and
is in the
u-th position where the corresponding sequence is
. The exchange of the two jobs yields
. Then, the objective function
F corresponding to the sequence
is subtracted from the
corresponding to
to obtain
It follows from Lemma 2 that
. When
, we have
. □
Lemma 7. In a given optimal sequence, the jobs in are ordered in the ascending order of .
Proof. Suppose that
and
are in the
x-th and
-th positions, separately. The original sequence and the sequence after swapping are
and
. Then, the difference between the two objective functions is
Obviously, , then when . □
Lemma 8. The deterioration rates of any job in are smaller than those of the jobs in .
Proof. Assuming that
and
are in the
u-th and
-th positions, the sequences before and after the exchange are
and
. And, the difference between the two is
According to Lemma 2, when there is . □
Suppose that
and
are in the
x-th and
y-th positions, respectively. That is, the sequence
, where
and
. The exchange of the two jobs yields
. Then, the objective function difference between the two is
If , should be placed at the x-th position; otherwise, should be placed at the y-th position.
From the analysis above, we can propose the algorithm to solve as follows
Theorem 1. The problem can be solved in .
Proof. The required time to calculate is , the required time to calculate and is constant, and required time, so the time required for Algorithm 1 is . □
Algorithm 1: Solution based on CONDW |
Input: N, , , , , , and . . Sort by increasing order of , i.e., . . According to Lemma 2, the optimal starting time and finishing time of due window are determined. . Determine the set , which contains jobs, namely, ,…,. . Identify the jobs in and through (31). Output: The optimal sequence , and . |
4. Solution of SLKDW
For the problem , the following properties can be given:
Lemma 9. For any given sequence of jobs, and in the optimal sequence are computed as times either the sum of the actual processing time of certain jobs or .
Proof. Case I. When
and
, where
. There is
When
, the objective function is
and
When
, the objective function can be written as
and
Obviously, when , there is ; otherwise .
Case II. When
, and
with
, and the function is
When
, the function is
and
When
, there is
and
If , ; otherwise .
Case III. When and with . It becomes Case II when either or ; it becomes Case I when either or . □
Lemma 10. For the optimal sequence, let and , where v and u, respectively, satisfy and ; and .
Proof. The objective function can be written as follows with
and
:
Case I. When
moves
units to the left with
, and
. Then, the function is
and
Obviously, .
When
moves
units to the right and
. Then, the function can be expressed as
It can be known that .
Case II. When
and
moves
units to the left, then
and
That is, .
When
and
moves
units to the right, then the function can be written as
and
Then, there is . □
According to Lemma 10, assuming that and in the optimal sequence. The following sets can be determined based on the due window: , and , in which is the job sequence.
Lemma 11. In the optimal sequence, the jobs in can be arranged in descending order of .
Proof. and
are the jobs at
x-th and
-th positions in
, respectively, where the sequence can be written as
. Swapping the two jobs yields
. Then, subtracting the function
F corresponding to
forms the
corresponding to
to obtain
If
,
. □
Lemma 12. In the optimal sequence, the jobs in can be arranged in any order of .
Proof. and are at the x-th and -th positions in , where . The sequences before and after the exchange are and . Since and do not change, we have . □
Lemma 13. In the optimal sequence, the jobs in can be sorted in the ascending order of .
Proof. and
are the jobs at the
x-th and
-th positions in
, namely, the sequence can be expressed as
, and
can be obtained by swapping the two jobs. And, the difference between the two is
When
, there is
. □
Lemma 14. The deterioration rates of any job in are less than .
Proof. and
are at the
-th and
v-th positions, the original sequence and the exchanged sequence are
, and
. And, the difference between the objective functions is
From the above equation, it can be seen that there is when . □
Lemma 15. The deterioration rates of all jobs in are less than .
Proof. and
are at the
-th and
u-th positions, the original and the exchanged sequence are
, and
. And, the difference between the functions is
Obviously, there is when . □
Assuming that
and
are the jobs at the
x-th and
y-th positions, the sequence can be written as
, where
and
. The two jobs are exchanged to obtain
. And, the function difference between the two sequences is
If , should be placed at the x-th position; otherwise, should be placed at the y-th position.
Theorem 2. The problem can be solved in by Algorithm 2.
Algorithm 2: Solution based on SLKDW |
Input: N, , , , , , and . . Sort according to . . According to Lemma 10, the optimal and of due window can be determined. . Determine the set , that is, . . Define the jobs in and through (56). Output: The optimal sequence , and . |
5. Solution of DIFDW
For the different due window () problem: , the following properties are proposed:
Lemma 16. For the job in a given sequence, the starting time and finishing time satisfy .
Proof. Obviously, .
Case I. For
. It can be seen that the job
is within the due window and does not incur any earliness/tardiness penalties. Then, the objective function of
is
Shift
to the left so that
, and the objective function is
Case II. For
, it can be observed that the job
is an early job, and the function is
Shift
and
to the left so that
, and the function is
In summary, . □
Lemma 17. For the given sequence, the optimal starting time and finishing time are as follows:
- (a)
If , and ;
- (b)
If , ;
- (c)
If , .
Proof. It can be known that
form Lemma 16 so that the objective function of
can be expressed as
According to Lemma 16, when , i.e., , there is to minimize the objective function; for and , namely , then and ; for and , that is, , there is to minimize the function. □
According to the three cases mentioned in the above lemma, the objective function is
Lemma 18. For an optimal sequence, the jobs are ranked in ascending order of deterioration rate .
Proof. and
are at the
x-th and
-th positions, the original and exchanged sequences are
and
. The difference between the two is
Obviously, when
, this satisfies
. □
Theorem 3. The problem can be solved in according to Algorithm 3.
Algorithm 3: Solution based on DIFDW |
Input: N, , , , , , and . . Determine the optimal sequence by . . Calculate and according to Lemma 17. Output: The optimal sequence . |
6. An Example
Consider an example with
,
, and
, and other parameters are detailed in the table below (i.e.,
Table 2):
For , the specific calculation steps are as follows:
. Since , .
. According to Lemma 2, and , and can be calculated, i.e., and . Then, the value of is .
. It can be known that is in the and in the third position in the sequence.
. For , . It can be calculated that , then place in the second position.
For , . It can be calculated that , then place in the fourth position.
For , . It can be calculated that , then place in the first position.
Thus, the optimal job sequence is , and and . And, the corresponding value of the objective function is .
For , the calculation process is as follows:
. Since , .
. According to Lemma 10, and . That is, and . And, the value of is .
. It can be known that and are in the , and in the second and third positions in the sequence.
. For , . It can be calculated that , then is placed in the fourth position.
For , . It can be calculated that , then is placed in the first position.
Thus, the optimal sequence is , and and . And, the corresponding value of function is .
For , the optimal sequence, and the staring times and finishing times are given as follows:
. The optimal sequence is , which is determined by .
. The starting time and finishing time can be shown as the following table (i.e.,
Table 3):
7. Conclusions
This paper studied single-machine delivery time scheduling with
and
. The objective is to find the optimal sequence, starting time and finishing time of the due window so that the position-dependent weighted sum of earliness, tardiness, starting time and size of the due window is to be minimized. Under common, slack, and different due windows, it is shown that the studied problems can all be solved within a time complexity of
. Future research could explore scheduling with linear deterioration functions in the context of flow shop setting, since, due to the complexity of the flow shop environment, heuristic algorithms may be proposed, such as the application of the gravitational search algorithm with hierarchy and distributed framework to it, as mentioned in Wang et al. [
28].