Let $$[a,b]\subseteq \mathbb {R}$$
[
a
,
b
]
⊆
R
be a non-empty and non singleton closed interval and $$P=\{a=x_0<\cdots <x_n=b\}$$
P
=
{
a
=
x
0
<
⋯
<
x
n
=
b
}
is a partition of it. Then $$f:I\rightarrow \mathbb {R}$$
f
:
I
→
R
is said to be a function of r-bounded variation, if the expression $$\sum \nolimits ^{n}_{i=1}|f(x_i)-f(x_{i-1})|^{r}$$
∑
i
=
1
n
|
f
(
x
i
)
-
f
(
x
i
-
1
)
|
r
is bounded for all possible partitions like P. One of the main results of the paper deals with the generalization of the classical Jordan decomposition theorem. We establish that for $$r\in ]0,1]$$
r
∈
]
0
,
1
]
, a function of r-bounded variation can be written as the difference of two monotone functions. While for $$r>1$$
r
>
1
, under minimal assumptions such a function can be treated as an approximately monotone function which can be closely approximated by a nondecreasing majorant. We also prove that for $$0<r_1<r_2$$
0
<
r
1
<
r
2
, the function class of $$r_1$$
r
1
-bounded variation is contained in the class of functions satisfying $$r_2$$
r
2
-bounded variations. We go through approximately monotone functions and present a possible decomposition for $$f:I(\subseteq \mathbb {R}_+)\rightarrow \mathbb {R}$$
f
:
I
(
⊆
R
+
)
→
R
satisfying the functional inequality $$f(x)\le f(x)+(y-x)^{p}\quad (x,y\in I \text{ with } x<y \text{ and } p\in ]0,1[ ).$$
f
(
x
)
≤
f
(
x
)
+
(
y
-
x
)
p
(
x
,
y
∈
I
with
x
<
y
and
p
∈
]
0
,
1
[
)
.
A generalized structural study has also been done in that specific section. On the other hand, for $$\ell [a,b]\ge d$$
ℓ
[
a
,
b
]
≥
d
, a function satisfying the following monotonic condition under the given assumption will be termed as d-periodically increasing $$f(x)\le f(y)\quad \text{ for } \text{ all }\quad x,y\in I\quad \text{ with }\quad y-x\ge d.$$
f
(
x
)
≤
f
(
y
)
for
all
x
,
y
∈
I
with
y
-
x
≥
d
.
We establish that in a compact interval any function satisfying d-bounded variation can be decomposed as the difference of a monotone and a d-periodically increasing function. The core details related to past results, motivation, structure of each and every section are thoroughly discussed below.