REVOLVING PROMISSORY NOTE

EXHIBIT 10.80

REVOLVING PROMISSORY NOTE

FOR VALUE RECEIVED, MANUGISTICS GROUP, INC. , a corporation organized under the laws of the State of Delaware (the “Company”), MANUGISTICS, INC., a corporation organized under the laws of the State of Delaware and MANUGISTICS ATLANTA, INC., a corporation organized under the laws of the State of Delaware (each a “Borrower” and collectively, the “Borrowers”) jointly and severally promise to pay to the order of SILICON VALLEY BANK, a California-chartered bank doing business in Virginia as “Silicon Valley East” (“Bank”), at such place as the holder hereof may designate, in lawful money of the United States of America, the aggregate unpaid principal amount of all advances (“Advances”) made by Bank to any Borrower in accordance with the terms and conditions of the Loan Agreement among Borrowers and Bank of even date herewith (as amended from time to time (the “Loan Agreement”), up to a maximum principal amount of Twenty Million Dollars ($20,000,000) (“Principal Sum”), or so much thereof as may be advanced or readvanced and remains unpaid. Borrowers shall also pay interest on the aggregate unpaid principal amount of such Advances, as follows:

Commencing as of the date hereof and continuing until repayment in full of all sums due hereunder, the unpaid Principal Sum shall bear interest at the variable rate of interest, per annum, most recently announced by Bank as its “prime rate,” whether or not such announced rate is the lowest rate available from Bank (the “Prime Rate”), plus one half of one percent (.50%) per annum. The rate of interest charged under this Note shall change immediately and contemporaneously with any change in the Prime Rate. All interest payable under the terms of this Note shall be calculated on the basis of a 360-day year and the actual number of days elapsed.

The unpaid Principal Sum, together with interest thereon at the rate or rates provided above, shall be payable as follows:

(a)           Interest only on the unpaid principal amount shall be due and payable monthly in arrears, commencing February 5, 2003, and continuing on the fifth (5 th ) day of each calendar month thereafter to maturity; and

(b)           Unless sooner paid, the unpaid Principal Sum, together with interest accrued and unpaid thereon, shall be due and payable in full on the Revolving Maturity Date.

The fact that the balance hereunder may be reduced to zero from time to time pursuant to the Loan Agreement will not affect the continuing validity of this Note or the Loan Agreement, and the balance may be increased to the Principal Sum after any such reduction to zero.

Each Borrower hereby represents, agrees and covenants that the Obligations evidenced hereby are deemed “Designated Senior Indebtedness” for purposes of that certain Indenture between the Company and State Street Bank and Trust Company dated October 20, 2000, as the same may be amended, restated or otherwise modified from time to time.

This Note is the “Revolving Promissory Note” described in the Loan Agreement, to which reference is hereby made for a more complete statement of the terms and conditions under which the Advances and Credit Extensions evidenced hereby are made. This Note may be secured as provided in the Loan Agreement. All capitalized terms used herein and not otherwise defined shall have the meanings given to such terms in the Loan Agreement.

Each Borrower irrevocably waives the right to direct the application of any and all payments at any time hereafter received by Bank from or on behalf of any Borrower and each Borrower irrevocably agrees that Bank shall have the continuing exclusive right to apply any and all such payments against the then due and owing obligations of either Borrower as Bank may deem advisable. In the absence of a specific determination by Bank with respect thereto, all payments shall be applied in the following order: (a) then due and payable fees and expenses; (b) then due and payable interest payments and mandatory prepayments; and (c) then due and payable principal payments and optional prepayments.

Bank is hereby authorized by each Borrower to endorse on Bank’s books and records each Advance made by Bank under this Note and the amount of each payment or prepayment of principal of each such Advance received by Bank; it being understood, however, that failure to make any such endorsement (or any error in notation) shall not affect the joint and several obligations of each Borrower with respect to Advances made hereunder, and payments of principal by any Borrower shall be credited to Borrowers notwithstanding the failure to make a notation (or any errors in notation) thereof on such books and records.

The occurrence of any one or more of the following events shall constitute an event of default (individually, an “Event of Default” and collectively, the “Events of Default”) under the terms of this Note:

(a)           The failure of either Borrower to pay to Bank within three (3) Business Days of whe