<PAGE>
 
                                                                     Exhibit 3.3

                           CERTIFICATE OF DESIGNATION

                                       of

                      SERIES A CONVERTIBLE PREFERRED STOCK

                                       of

                                CONSILIUM, INC.

       (Pursuant to Section 151 of the Delaware General Corporation Law)


     Consilium, Inc., a corporation organized and existing under the General
Corporation Law of the State of Delaware (the "Corporation"), hereby certifies
that the following resolutions were adopted by the Board of Directors of the
Corporation as required by Section 151 of the General Corporation Law by
unanimous written consent of the Board of Directors dated August 15, 1997:

     RESOLVED, that pursuant to the authority granted to and vested in the Board
of Directors of this Corporation (the "Board") in accordance with the provisions
of the Certificate of Incorporation, the Board hereby creates a series of
preferred stock of the Corporation, par value $.01 per share (the "Preferred
Stock"), and hereby states the designation and number of shares, and fixes the
relative rights, preferences, and limitations thereof as follows:

     Section 1.    Designation and Amount.  The shares of such series shall be
                   ----------------------                                     
designated as "Series A Convertible Preferred Stock" (the "Series A Preferred
Stock") and the number of shares constituting the Series A Preferred Stock shall
be three thousand (3,000).  Such number of shares may be increased or decreased
by resolution of the Board; provided, however, no decrease shall reduce the
number of shares of Series A Preferred Stock to a number less than the number of
shares then outstanding plus the number of shares reserved for issuance upon the
exercise of outstanding options, rights, or warrants for, or upon the conversion
of any outstanding securities issued by the Corporation convertible into Series
A Preferred Stock.

     Section 2.    Dividends.
                   --------- 

             a.    Subject to the limitations set forth below, the holders of
the Series A Preferred Stock shall be entitled to receive, from funds of the
Corporation legally available therefor pursuant to the General Corporation Law
of the State of Delaware (the "Legally Available Funds"), a cumulative dividend
of $80 per annum on each share of Series A Preferred Stock ratably for the
period that such share of the Series A Preferred Stock is outstanding (the
"Period").

             b.    Subject to the limitations set forth herein and by applicable
state law, dividends on each share of Series A Preferred Stock shall be due and
payable on or before the fifth business day following the Conversion Date (as
defined below) with respect to such share 
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or the Anniversary Date (as defined below), whichever is applicable, and shall
paid to the holder of record of such share as such holder appears on the stock
register of the Corporation on the Conversion Date or the Anniversary Date,
whichever is applicable.

             c.    Dividends on shares of Series A Preferred Stock shall be
fully cumulative and shall accrue without regard to whether or not such
dividends have been declared and whether or not there are any Legally Available
Funds available for the payment of dividends.

             d.    Dividends on the shares of Series A Preferred Stock shall be
payable in cash, common stock of the Corporation, $0.01 par value per share (the
"Common Stock"), or any combination thereof, as determined by the Board.  Any
Common Stock so issued as a dividend shall be deemed to have a value equal to
the average of the closing bid prices of the Common Stock as reported on the
National Association of Securities Dealers Automated Quotation System ("NASDAQ")
(or on the principal national securities exchange on which the Common Stock is
admitted to trading or listed or, if not listed or admitted to trading on NASDAQ
or a national securities exchange, as reported by the National Quotation Bureau,
Inc. or other similar organization ("Other Exchanges") ) for the five (5)
trading days immediately prior to the date such dividend is payable.

             e.    No share of Series A Preferred Stock shall be entitled to
participate with respect to any dividend (in any form) declared, accrued, or
paid on any other class, or series thereof, of the capital stock of the
Corporation.

     Section 3.    Conversion.
                   ---------- 

             a.    The holder of any share or shares of Series A Preferred Stock
shall have the right, without the payment of any additional consideration, to
convert any share of Series A Preferred Stock held by such holder into that
number of fully paid and non-assessable shares of Common Stock as is determined
by dividing $1,000 by the Conversion Price using the following Conversion
Schedule:

             Six (6) months from the Closing Date holders shall have the right
to convert twenty five (25%) percent of their total outstanding position, only
if the Closing Price reported on NASDAQ or Other Exchanges is five ($5.00)
dollars or above, at a fifteen (15%) percent discount from the Average Bid Price
of the five (5) trading days prior to the Conversion Date; provided, however,
the Company shall not be obligated to convert an aggregate number of Shares of
Series A Preferred Stock greater than twenty-five (25%) percent of the number of
designated shares of Series A Preferred Stock.

             Nine (9) months from the Closing Date holders shall have the right
to convert an additional twenty-five (25%) percent of its total outstanding
position, only if the Closing Price reported on NASDAQ or Other Exchange is five
($5.00) dollars or above, at a seventeen (17%) percent discount from the Average
Bid Price of the five (5) trading days prior to the Conversion Date; provided,
however, the Company shall not be obligated to convert an aggregate number of

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Shares of Series A Preferred Stock greater than fifty (50%) percent of the
number of designated shares of Series A Preferred Stock.

             One (1) year from the Closing Date the holder shall have right to
convert any unconverted Preferred Stock at an eighteen (18%) percent discount
from the five (5) day Average Bid Price prior to the Conversion Date.

             As used herein, the Conversion Price shall mean a price equal to
the above discount from the Average Bid Price (as hereinafter defined),
provided, however, in no event shall the Conversion Price be less than $1.95
(the "Floor Price") or more than the difference between the Closing Bid Price
and the Floor Price added to the Closing Bid Price (the "Ceiling Price"). The
formula for such calculation shall be stated as follows:

             Ceiling Price = Closing Bid Price - $1.95 + Closing Bid Price

             The holder shall exercise its right to convert the Preferred Stock
by telecopying an executed and completed Notice of Conversion (Exhibit A annexed
hereto) to the Company and delivering the original Notice of Conversion and the
certificate representing the Preferred Stock to the Company by express courier.
Each business date on which a Notice of Conversion is telecopied to and received
by the Company in accordance with the provisions hereof shall be deemed a
conversion date. The Company will use its best efforts to transmit the
certificates representing shares of Common Stock issuable upon conversion of any
Preferred Stock (together with the certificates representing the Preferred Stock
not so converted) to the holder via express courier, by electronic transfer or
otherwise within three business days after the conversion date if the Company
has received the original Notice of Conversion and Preferred Stock certificate
being so converted by such date. In addition to any other remedies which may be
available to the holder, in the event that the Company fails to use its best
efforts to effect delivery of such shares of Common Stock within such three
business day period, the holder will be entitled to revoke the relevant Notice
of Conversion by delivering a notice to such effect to the Company whereupon the
Company and the holder shall each be restored to their respective positions
immediately prior to delivery of such Notice of Conversion.

             In the event that the Common Stock issuable upon conversion of the
Preferred Stock is not delivered, as a direct result of the negligence or action
or inaction of the Company only, within ten (10) business days of receipt by the
Company of a valid Conversion Notice and the Preferred Stock to be converted
(such date of receipt referred to as the "Conversion Date"), and (i) the closing
price of the Common Stock of the Company on the Nasdaq National Market on the
date the Common Stock issuable upon conversion of the Preferred Stock is
delivered to the Purchaser (the "Delivery Date") is lower than the Conversion
Price, or (ii) the Delivery Date is not within fifteen (15) business days of the
Conversion Date, the Company shall pay to the Purchaser, in immediately
available funds, upon demand, as liquidated damages for such failure and not as
a penalty, for each $100,000 of Preferred Stock sought to be converted, $500 for
each of the first ten (10) days and $1,000 per day thereafter that the
Conversion Shares are not delivered, which liquidated damages shall run from the
tenth or fifteenth business day after the Conversion Date. Any and all payments
required pursuant to this paragraph shall be payable

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only in shares of Common Stock and not in cash. The number of such shares shall
be determined by dividing the total sum payable by the Conversion Price.

          b.   Any shares of Series A Preferred Stock outstanding on the second
anniversary of the date on which the Series A Preferred Stock was first issued
by the Corporation (the "Anniversary Date") automatically shall be converted
into Common Stock on the same basis as the holder of such shares of Series A
Preferred Stock may convert such shares pursuant to Section 3a above. The
Corporation shall not be obligated to deliver the certificate(s) evidencing such
shares of Common Stock unless the certificate(s) evidencing the Series A
Preferred Stock so converted are delivered to the Corporation.

          c.   (1)  If the Corporation shall, at any time or from time to time,
declare and pay to the holders of Common Stock a dividend in shares of Common
Stock, or the Corporation shall subdivide the outstanding shares of Common Stock
into a greater number of shares of Common Stock, or combine the outstanding
shares of Common Stock into a smaller number of shares of Common Stock then the
Floor Price, each shall be adjusted so that the same shall equal the price
determined by multiplying the Floor Price by a fraction, the numerator of which
shall be the number of shares of Common Stock issued and outstanding immediately
prior to the happening of such even and the denominator of which shall be the
number of shares of Common Stock issued and outstanding immediately after the
happening of such event. Such adjustment shall become effective immediately
after the opening of business of the day following the record date, in the event
of a stock dividend or the day upon which the subdivision or combination becomes
effective, as the case may be.

               (2)  If the Corporation shall, at any time or from time to time
after the date on which the Series A Preferred Stock was first issued by the
Corporation, make or issue, or fix a record date for the determination of
holders of shares of Common Stock entitled to receive a dividend or other
distribution payable in securities of the Corporation, including a distribution
of evidence of indebtedness of the Corporation, other than shares of Common
Stock, then, and in each such event, provision shall be made by the Corporation
so that the holders of shares of Series A Preferred Stock shall receive upon
conversion thereof, in a addition to the number of shares of Common Stock
receivable thereupon, the amount of those securities of the Corporation that
such holders would have received had their shares of Series A Preferred Stock
been converted on the date of such even and had they thereafter, during the
period from the date of such event to and including the date of conversion,
retained such securities receivable by them as aforesaid during such period.

               (3)  If the shares of Common Stock issuable upon the conversion
of shares of Series A Preferred Stock shall be changed into the same or any
different number of shares of any class or any series of any class of capital
stock, whether by capital reorganization, reclassification or otherwise (other
than a subdivision or combination of shares or a stock dividend provided for
above, or a reorganization, merger, consolidation or sale of assets provided for
in section 7 hereof), then, and in each such event, the holder of shares of
Series A Preferred Stock shall have the right thereafter to convert such shares
of Series A Preferred Stock into the kind and amount of shares of stock and
other securities and property receivable upon such

                                       4
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reorganization, reclassification or other change by holders of the number of
shares of Common Stock into which such shares of Series A Preferred Stock might
have been converted immediately prior to such reorganization, reclassification
or change.

             e.    At all times, the Corporation shall reserve and keep
available out of its authorized but unissued Common Stock solely for issuance
upon the conversion of shares of the Series A Preferred Stock as herein
provided, such number of shares of Common Stock as, from time to time, shall be
issuable upon the conversion of all the shares of the Series A Preferred Stock
at the time outstanding.

             f.    No fractional shares of Common Stock shall be issued. In lieu
of the issuance of any fractional share of Common Stock that would, but for the
foregoing, be issued to a holder of Series A Preferred Stock on the conversion
thereof, the Corporation shall pay to such holder, in cash, the value of such
fractional share which value shall be based upon the closing sale price of the
Common Stock as reported on NASDAQ (or on the principal national securities
exchange on which the Common Stock is admitted to trading or listed or, if not
listed or admitted to trading on NASDAQ or a national securities exchange, as
reported by the National Quotation Bureau, Inc. or other similar organization)
for the trading day immediately preceding the effective date of such conversion.

     Section 4.    Voting Rights.  Except as required by applicable law, the
                   -------------                                            
holders of shares of Series A Preferred Stock shall not have the right or power
to vote on any question or in any proceeding or to be represented at, or to
receive notice of, any meeting of the Corporation's stockholders.

     Section 5.    Reacquired Shares.  Any shares of Series A Preferred Stock
                   -----------------                                         
purchased or otherwise acquired by the Corporation in any manner whatsoever
shall be retired and canceled promptly after the acquisition thereof.  All such
shares shall upon their cancellation become authorized by unissued shares of
Preferred Stock and may be reissued as part of a new series of Preferred Stock
subject to the conditions and restrictions on issuance set forth herein, in the
Certificate of Incorporation, or in any other Certificate of Designation
creating a series of Preferred Stock or any similar stock or as otherwise
required by law.

     Section 6.    Liquidation, Dissolution or Winding Up.  In the event of any
                   --------------------------------------                      
liquidation, dissolution, or winding up of the Corporation, the holders of
shares of the Series A Preferred Stock are entitled to receive out of assets of
the Corporation available for distribution to stockholders, after satisfaction
of indebtedness, but before any distribution of assets is made to holders of
Common Stock or to holders of any other class of stock of the Corporation
ranking junior to the Series A Preferred Stock upon liquidation, liquidating
distributions on each share of Series A Preferred Stock held by such holder in
the per share amount of $1,000 plus all dividends accrued and unpaid, if any, on
each such share pursuant to Section 2 hereof (the "Liquidation Preference").
If, upon any liquidation, dissolution or winding up of the Corporation, the
amounts payable with respect too the Series A Preferred Stock  or any other
shares of stock of the Corporation ranking as to any such distribution on a
parity with the Series A Preferred Stock are not paid in full, the holders of
the Series A Preferred and of such other shares will share ratably 

                                       5
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in any such distribution of assets of the Corporation in proportion to the full
distributable amounts to which they are entitled. After payment of the full
amount of the liquidating distribution to which they are entitled, the holders
of shares of the Series A Preferred Stock will not be entitled to any further
participation in any distribution of assets by the Corporation.

     Section 7.    Consolidation, Merger, etc.  If the Corporation shall enter
                   --------------------------                                 
into any consolidation, merger, combination or other transaction in which the
shares of Common Stock are exchanged for or changed into other stock or
securities, cash and/or any other property, then, in any such case, the
Corporation, as a condition precedent to such transaction, shall cause effective
provisions to be made so that each holder of Series A Preferred Stock then
outstanding shall have the right, by converting such share(s) of Series A
Preferred Stock to acquire the kind and amount of shares of stock, securities,
cash and/or other property receivable upon such consolidation, merger,
combination or other transaction by a holder of the number of shares of Common
stock which might have been acquired upon conversion of such Series A Preferred
Stock immediately prior to such consolidation, merger, combination, or other
transaction.

     Section 8.    No Redemption.  The shares of Series A Preferred Stock shall
                   -------------                                               
not be redeemable.

     Section 9.    Amendment.  This Certificate of Designation shall not be
                   ---------                                               
amended in any manner which should materially alter or change the powers,
preferences, or special rights of the Series A Preferred Stock so as to affect
them adversely without the affirmative vote of the holders of at least two-
thirds of the outstanding shares of Series A Preferred Stock, voting together as
a single class.

     RESOLVED, FURTHER, that the appropriate officers of the Corporation hereby
are authorized to execute and acknowledge a certificate setting forth these
resolution and to cause such certificate to be filed and recorded, all in
accordance with the requirements of Section 151 of the General Corporation Law
of the State of Delaware.

     IN WITNESS WHEREOF, this Certificate of Designation is executed on behalf
of the Corporation by its President and Chief Executive Officer this ___ day of
August, 1997.



                                    -------------------------------------
                                    Laurence R. Hootnick
                                    President and Chief Executive Officer

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                                                                       EXHIBIT A


                             NOTICE OF CONVERSION

       (To be Executed by the Registered Holder in order to Convert the
                        8% Convertible Preferred Stock)

The undersigned hereby irrevocably elects to convert the Preferred Stock
Certificate No. _________ into Shares of Common Stock of CONSILIUM, INC. (the
"Company") according to the conditions hereof, as of the date written below.

The undersigned represents and warrants that:

       (i)    that all offers and sales by the undersigned of the shares of
              Common Stock issuable to the undersigned upon conversion of the
              Preferred Stock shall be made pursuant to an exemption from
              registration under the Act, or pursuant to registration of the
              Common Stock under the Securities Act of 1933, as amended (the
              "Act"), subject to any restrictions on sale or transfer set forth
              in the Subscription Agreement between the Company and the original
              holder of the Preferred Stock submitted herewith for conversion;

       (ii)   the undersigned has not engaged in any transaction or series of
              transaction that is a part of or a plan or scheme to evade the
              registration requirements of the Act; and

       (iii)  upon conversion pursuant to this Notice of Conversion, the
              undersigned will not own or deemed to beneficially own (within the
              meaning of the 1934 Act) 4.9% or more of the then issued and
              outstanding shares of the Company.


       --------------------------------       ----------------------------------
       Date of Conversion                     Applicable Conversion Price

       
       --------------------------------       ----------------------------------
       Number of Common Shares upon           $ Amount of Conversion
       Conversion


       --------------------------------       ----------------------------------
       Signature                              Name

       Address:                               Delivery of Shares to:



* This original Preferred Stock and Notice of Conversion must be received by
the Company by the third business day following the Date of Conversion.