<PAGE>


                                                                   Exhibit 10.21

                        SEPARATION AND RELEASE AGREEMENT
                        --------------------------------

     This Separation and Release Agreement (the "Agreement"), dated this _____
day of July, 2001, by and between Robert E. O'Neil, Jr. ("O'Neil") and Open Plan
Systems, Inc., a Virginia corporation (the "Company") provides:

     1.   Termination of Employment; Separation Benefits.
          ----------------------------------------------

     O'Neil's employment terminated effective July 31, 2001 ("Termination Date")
pursuant to O'Neil's voluntary resignation. In consideration of O'Neil's
acceptance of this Agreement, the Company shall pay to O'Neil a gross sum
equivalent to two (2) months' salary continuation at Employee's last regular
rate of pay. This sum shall be paid to Employee in regular installments over a
two-month period, each coinciding with the Company's regularly scheduled pay
days and commencing with the first pay day following the Effective Date of this
Agreement (as hereinafter defined). O'Neil hereby agrees that the Company will
deduct from such payment all withholding taxes and other payroll deductions that
the Company is required by law to make from wage payments to employees. O'Neil
hereby further agrees that the payments and performances described in this
Agreement are all that O'Neil shall be entitled to receive from the Company
except for vested qualified retirement benefits, if any, to which O'Neil may be
entitled under the Company's ERISA plans.

     2.   No Obligation to Make Payment under Normal Policies.
          ---------------------------------------------------

     O'Neil hereby agrees and acknowledges that the benefits set forth in first
Paragraph of this Agreement are more than the Company is required to do under
its normal policies and procedures and that they are in addition to anything of
value to which O'Neil already is entitled.

<PAGE>

     3.   Complete Release.
          ----------------

     O'Neil hereby knowingly and voluntarily releases and forever discharges the
Company, any related companies, and the former and current employees, officers,
agents, directors, shareholders, investors, attorneys, affiliates, successors
and assigns of any of them (the "Released Parties") from all liabilities,
claims, demands, rights of action or causes of action O'Neil had, has or may
have against any of the Released Parties, including but not limited to any
claims or demands based upon or relating to O'Neil's employment with the Company
or the termination of that employment. This includes but is not limited to a
release of any rights or claims O'Neil may have under Title VII of the Civil
Rights Act of 1964, which prohibits discrimination in employment based on race,
color, national origin, religion or sex; the Equal Pay Act, which prohibits
paying men and women unequal pay for equal work; the Age Discrimination in
Employment Act of 1967, which prohibits age discrimination in employment; the
Americans with Disabilities Act, which prohibits discrimination against
otherwise qualified disabled individuals; the Virginia Human Rights Act, which
is a state statute prohibiting, among other things, employment discrimination;
or any other federal, state or local laws or regulations prohibiting employment
discrimination. This also includes but is not limited to a release by O'Neil of
any claims for wrongful discharge, breach of contract, or any other statutory,
common law, tort or contract claim that O'Neil had, has or may have against any
of the Released Parties. This release covers both claims that O'Neil knows about
and those O'Neil may not know about.

                                      -2-

<PAGE>

     This release does not include, however, a release of O'Neil's right, if
any, to payment of vested qualified retirement benefits under the Company's
ERISA plans and the right to continuation in Company medical plans as provided
by COBRA.

     4.   No Future Lawsuits.
          ------------------

     O'Neil promises never to file a lawsuit asserting any claims that are
released in Paragraph 3. O'Neil further agrees that, in the event he breaches
this Paragraph 4, he shall pay to the Company all of its expenses incurred as a
result of such breach, including but not limited to, reasonable attorney's fees
and expenses.

     5.   Disclaimer of Liability.
          -----------------------

     This Agreement and the payments and performances hereunder are made solely
to assist O'Neil in making the transition from employment with the Company, and
are not and shall not be construed to be an admission of liability, an admission
of the truth of any fact, or a declaration against interest on the part of the
Company.

     6.   Confidential Information.
          ------------------------

     A.   O'Neil covenants and agrees that he shall not use, divulge, publish or
disclose to any person or organization, confidential information obtained by
O'Neil during the course of O'Neil's employment or related to O'Neil's cessation
of employment ("Confidential Information"). The Confidential Information
consists of the following: (a) the existence and terms of this Agreement itself;
(b) personal, financial, private or sensitive information concerning the
Company's executives, employees, customers and suppliers; (c) information
concerning the Company's sources of business contacts, business records,
customer lists or other client

                                      -3-

<PAGE>

information, business documents and forms, customer contracts, pricing and
customer service requirements; (d) information concerning the Company's
formulas, designs, methods of business, trade secrets, technology, business
operations, business records and files; and (e) any other non-public information
which, if used, divulged, published or disclosed by O'Neil, would be reasonably
likely to provide a competitive advantage to a competitor or to cause any of the
Company's executives or employees embarrassment. O'Neil further agrees to return
immediately to the Company all of the Company's property, if any, in O'Neil's
possession or under O'Neil's control. Notwithstanding the restrictions contained
in this Subsection A, O'Neil shall be permitted to make necessary disclosures to
members of his immediate family or his attorneys and advisors concerning the
terms of this Agreement.

     B.   The parties hereto agree that given the nature of the positions held
by O'Neil with the Company, the covenants and restrictions set forth in
Subsection A above are reasonable and necessary for the protection of the
significant investment of the Company in developing, maintaining and expanding
its business. Accordingly, the parties hereto agree that in the event of any
breach by O'Neil of any of the provisions of Subsection A that monetary damages
alone will not adequately compensate the Company for its losses and therefore it
is entitled to injunctive relief. In addition, the Company is entitled to
recover from O'Neil all damages, including actual and consequential damages,
costs and expenses, including legal costs and actual attorney's fees, incurred
by it as a result of such breach.

                                      -4-

<PAGE>

     7.   Claim for Reinstatement.
          -----------------------

     Employee agrees to waive and abandon any claim to reinstatement with the
Company. Employee further agrees not to apply for any position of employment
with the Company and agrees that this Agreement shall be sufficient
justification for rejecting any such application.

     8.   Statements Regarding Company and/or Employment.
          ----------------------------------------------

     O'Neil agrees not to do or say anything that reasonably may be expected to
have the effect of criticizing or disparaging the Company, any director of the
Company, any of the Company's employees, officers or agents, or diminishing or
impairing the goodwill and reputation of the Company or the products and
services it provides. O'Neil further agrees not to assert that any current or
former employee, agent, director or officer of the Company has acted improperly
or unlawfully with respect to O'Neil or any other person regarding employment.

     9.   Other Promises.
          --------------

     A.   O'Neil agrees that, unless compelled by law, O'Neil shall not,
directly or indirectly, assist any person or entity in connection with any
potential or actual litigation against the Company or any other of the Released
Parties described in Paragraph 3 hereof.

     B.   O'Neil agrees that: (i) he shall not solicit Company proxies, or
participate in an election contest for Company directors or assist, counsel or
communicate with any other person in connection with any such proxy solicitation
or proxy contest; (ii) he shall not deposit Company voting shares in a voting
trust or subject Company shares to a voting agreement; (iii) he shall not
initiate or solicit shareholder proposals, and he shall not participate in,
assist, or support any effort to do so; and (iv) he shall not take, participate
in, or support any action to
                                      -5-

<PAGE>

acquire or affect control of Company or to encourage or assist any other person
or entity to do so. However, nothing in this Paragraph shall prohibit O'Neil
from voting or selling any Company shares that he owns on the date hereof.

     10.  Non-Release of Future Claims.
          ----------------------------

     This Agreement does not waive or release any rights or claims that O'Neil
may have under the Age Discrimination in Employment Act or other law which arise
after the date that O'Neil signs this Agreement.

     11.  Period for Review and Consideration of Agreement.
          ------------------------------------------------

     O'Neil understands that O'Neil has been given a period of twenty-one (21)
days to review and consider this Agreement before signing it. O'Neil further
understands that O'Neil may use as much of this 21-day period as O'Neil wishes
prior to signing.

     12.  Encouragement to Consult with Attorney.
          --------------------------------------

     O'Neil is encouraged to consult with an attorney before signing this
Agreement. O'Neil represents that he has, in fact, done so.

     13.  O'Neil's Right to Revoke Agreement.
          ----------------------------------

     O'Neil may revoke this Agreement within seven (7) days of O'Neil's signing
it. Revocation can be made by delivering a written notice of revocation to
Robert E. Spicer, Jr. at Williams, Mullen, Clark & Dobbins, 1021 East Cary
Street, P.O. Box 1320, Richmond, Virginia 23218. For this revocation to be
effective, written notice must be received by Mr. Spicer no later than the close
of business on the seventh day after O'Neil signs this Agreement. If O'Neil has
not

                                       -6-

<PAGE>

revoked the Agreement, the eighth (8/th/) day after O'Neil signs this
Agreement shall be the Effective Date for purposes of this Agreement.

     14.  Acknowledgment.
          --------------

     O'Neil acknowledges that he has signed this Agreement freely and
voluntarily without duress of any kind.

     15.  Entire Agreement.
          ----------------

     This Agreement contains the entire understanding of O'Neil and the Company
concerning the subjects it covers and it supersedes all prior understandings and
representations. The acquire or affect control of Company or to encourage or
assist any other person or entity to do so. However, nothing in this Paragraph
shall prohibit O'Neil from voting or selling any Company shares that he owns on
the date hereof.

     10.  Non-Release of Future Claims.
          ----------------------------

     This Agreement does not waive or release any rights or claims that O'Neil
may have under the Age Discrimination in Employment Act or other law which arise
after the date that O'Neil signs this Agreement.

Company has made no promises to O'Neil other than those set forth herein. This
Agreement may not be modified or supplemented except by a subsequent written
agreement signed by all parties.

     16.  Successorship.
          -------------

     It is the intention of the parties that the provisions hereof be binding
upon the parties, their employees, affiliates, agents, heirs, successors and
assigns forever.

     17.  Governing Law.
          -------------

     This Agreement shall be governed by the laws of the Commonwealth of
Virginia.

                                      -7-

<PAGE>

     O'NEIL ACKNOWLEDGES THAT HE HAS READ THIS AGREEMENT, UNDERSTANDS IT, AND IS
VOLUNTARILY ENTERING INTO IT. PLEASE READ THIS AGREEMENT CAREFULLY. IT CONTAINS
A RELEASE OF ALL KNOWN AND UNKNOWN CLAIMS.

<TABLE>
<S>                                                  <C>
         8/31/01                                              /s/ Robert E. O'Neil, Jr.
---------------------------                          ----------------------------------------------------------
Date                                                 Robert E. O'Neil, Jr.

COMMONWEALTH OF VIRGINIA

City/County of    Richmond     , to-wit:
               ----------------

Subscribed and sworn to me this      13/th/  day of   August  , 2001, by Robert E. O'Neil, Jr
                                -------------        ----------


                                                                              /s/ Betty G. Hale
                                                                   --------------------------------------------
                                                                              Notary Public

My commission expires:     6/30/2001
                       ------------------------------


                                                              OPEN PLAN SYSTEMS, INC.


         8/17/01                                     By:      /s/ David E. Green
---------------------------                               -----------------------------------------------------
Date

                                                     Its:     Vice President
                                                           ----------------------------------------------------

 COMMONWEALTH OF VIRGINIA

City/County of    Henrico  , to-wit:
               ------------

Subscribed and sworn to me this    7/th/  day of   Sept.      , 2001, by        Dave Green
                                ---------        -------------           -----------------


                                                                       /s/ Debra Vaughton
---------------------------------------------------------------------------------------------------------------
                                                                            Notary Public
My commission expires:     12/31/2001
                       ---------------------------------------

</TABLE>

                                      -8-