Some times our requirement comes like we can not use any of standard scheduling functions available to start a process chain or an infopackage or a Job.

Ex: Process chain has to start at 3 different Odd times in a day(like: 7, 12, 20 hours).
Or some chains has to be started based on some other loads success or failure...
Or we have to use same process chain multiple times instead of including more infopacakges...etc

For above requirements, to control process chain effectively it better to start Process chain or Job or infopackage through an Event.

T Code : SM62 --> To Create an Event.
T Code : SE38 --> To Create an ABAP Program
Use Function Module : BP_EVENT_RAISE to raise an event.

Scenario: First day of week weekly load has to start first. Remaining days in weeks daily load has to run 2 different times in a day(ex: 6 and 20 hours)

Steps:

1. Create a Process Chain1 and Schedule it based on event and check periodic check box.

2. Create a Process Chain2 and include below ABAP program and schedule it for every one hour(24 X7) periodically. So this chain will trigger Process Chain1, based on conditions specified in ABAP Program.

3. See below doc : How to ... Integrate ABAP Program in Process Chain

https://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/docs/library/uuid/3507aa90-0201-0010-6891-d7df8c4722f7

Sample Coding:
SELECTION-SCREEN BEGIN OF BLOCK Daily_Loads WITH FRAME TITLE TEXT-001.
SELECTION-SCREEN COMMENT /1(50) COMM0001.
Parameters : Dly_Ld1(2) type c.
Parameters : Dly_Ld2(2) type c.
SELECTION-SCREEN END OF BLOCK Daily_Loads.

SELECTION-SCREEN BEGIN OF BLOCK Weekly_Load WITH FRAME TITLE TEXT-002.
SELECTION-SCREEN COMMENT /1(50) COMM0002.
Parameters : Wkly_Ld1(2) type c.
SELECTION-SCREEN END OF BLOCK Weekly_Load.

Data : hour(2) type c.
Data: l_cweek type /BI0/OICALWEEK.
Data: l_fdate type /BIC/OISSS_DATE.
Data: l_date type /bic/OISSS_DATE.

INITIALIZATION.
MOVE 'Input Daily Load Timings in 24Hour Format' TO COMM0001.
MOVE 'Input Weekly Load Timings in 24Hour Format' TO COMM0002.
clear hour.
hour = sy-timlo(2).

****Code to get First day of Fiscal Week
CALL FUNCTION 'ZBW_DATE_GET_FISCAL_WEEK'
EXPORTING
DATE = sy-datum
IMPORTING
WEEK = l_cweek.

CALL FUNCTION 'WEEK_GET_FIRST_DAY'
EXPORTING
WEEK = l_cweek
IMPORTING
DATE = l_fdate .
move sy-datum to l_date.

START-OF-SELECTION.
if l_fdate = l_date and hour = Wkly_Ld1.

CALL FUNCTION 'BP_EVENT_RAISE'
EXPORTING
EVENTID = 'SSS_OBSS_WEEKLY_LOAD'
* EVENTPARM = ' '
* TARGET_INSTANCE = ' '
* EXCEPTIONS
* BAD_EVENTID = 1
* EVENTID_DOES_NOT_EXIST = 2
* EVENTID_MISSING = 3
* RAISE_FAILED = 4
* OTHERS = 5.
elseif hour = Dly_Ld1 or hour = Dly_Ld2.

CALL FUNCTION 'BP_EVENT_RAISE'
EXPORTING
EVENTID = 'SSS_OB_SALES_DATA_LOAD'
* EVENTPARM = ' '
* TARGET_INSTANCE = ' '
* EXCEPTIONS
* BAD_EVENTID = 1
* EVENTID_DOES_NOT_EXIST = 2
* EVENTID_MISSING = 3
* RAISE_FAILED = 4
* OTHERS = 5 .
IF SY-SUBRC <> 0.
* MESSAGE ID SY-MSGID TYPE SY-MSGTY NUMBER SY-MSGNO
* WITH SY-MSGV1 SY-MSGV2 SY-MSGV3 SY-MSGV4.
ENDIF.

While execution we can specify Daily load and weekly load times in selection screen(as below). We can create variant and assign in process chain to automate.
Provide values in selection screen and save a variant.