Getting Cumulative Sum (Running Total) Using Analytical Functions in oralce

SELECT
    DEPTNO,
    ENAME,
    SAL,
    SUM(SAL) OVER (PARTITION BY DEPTNO ORDER BY SAL,ENAME) CUMDEPTTOT,
    SUM(SAL) OVER (PARTITION BY DEPTNO) DEPTTOTAL,
    SUM(SAL) OVER (ORDER BY DEPTNO, SAL) CUMTOT,
    SUM(SAL) OVER () TOTSAL
FROM
    SCOTT.EMP
ORDER BY
    DEPTNO

  SELECT COMPANY,

           ORDER_NO,

           CUSTOMER_ID,

           INVOICE_ID,

           SUM(OPEN_AMOUNT*(0.2)/365*DDD) AS DELAY_CHARGE_CAL

    FROM 

    (

    SELECT CCPP.COMPANY,

           CCPP.ORDER_NO,

           IDENTITY AS CUSTOMER_ID,

           CCPP.INVOICE_ID,

           PP.INSTALLMENT_ID,

           to_char(to_date(DUE_DATE,'DD-MON-RR'),'DD-MON-RR') DUE_DATE, 

           to_number(to_char(last_day(DUE_DATE),'dd')) DD,

           SUM(to_number(to_char(last_day(DUE_DATE),'dd'))) OVER (ORDER BY DUE_DATE) DDD,

           C_Credit_Account_Hist_API.Get_Open_Amount(CCPP.COMPANY, CCPP.INVOICE_ID, INSTALLMENT_ID) OPEN_AMOUNT

           C_Credit_Account_Hist_API.Get_Open_Amount(CCPP.COMPANY, CCPP.INVOICE_ID, INSTALLMENT_ID)*.2/365*SUM(to_number(to_char(last_day(DUE_DATE),'dd'))) OVER (ORDER BY DUE_DATE) DC

    FROM C_CREDIT_PAYMENT_PLAN CCPP, 

            PAYMENT_PLAN PP 

    WHERE CCPP.COMPANY=PP.COMPANY

      AND CCPP.INVOICE_ID=PP.INVOICE_ID

      AND CCPP.ORDER_NO=ORDER_NO_

      AND PP.INSTALLMENT_ID<>'1'

      AND to_date(DUE_DATE,'DD-MON-RR')<=REPORT_DATE_

      ORDER BY to_date(DUE_DATE,'DD-MON-RR')

    )

    GROUP BY COMPANY,

             ORDER_NO,

             CUSTOMER_ID,

             INVOICE_ID