<PAGE>

                                                                   EXHIBIT 10.40

                     MANAGEMENT CHANGE IN CONTROL AGREEMENT

      MANAGEMENT CHANGE IN CONTROL AGREEMENT entered into this 15th day of
October 2004, by and among Concord Communications, Inc., a Massachusetts
corporation ("Concord"), and the undersigned employee of Concord, Ted D.
Williams (the "Employee").

                                   WITNESSETH:

      WHEREAS, Concord and the Employee desire to set forth certain terms and
conditions relating to benefits to be afforded to Employee during the course of
employment and sets forth certain terms and conditions relating to benefits to
be afforded to Employee upon the occurrence of a Change in Control (as
hereinafter defined) of Concord;

      NOW THEREFORE, in consideration of the premises and of the mutual
covenants and agreements hereinafter set forth, the parties hereto hereby agree
as follows:

      1. Severance and Option Acceleration. (a) during the Term (as hereinafter
defined), if within six (6) months of a Change in Control of Concord, Concord
(or any successor corporation) terminates (each, a "Termination Event") the
Employee's employment without Cause (as hereinafter defined) or the employee
voluntarily terminates his/her employment for Good Reason (as hereinafter
defined), the Employee shall receive a single severance payment in cash in an
amount equal to six months' base annual salary (at the rate being paid to
him/her immediately prior to such termination) (the "Severance Benefit"). If a
Termination Event occurs, and the Employee receives the Severance Benefit, then
he shall not be entitled to continue to receive (i) any other salary or bonus or
the severance benefit referenced in Section 2(b) or (ii) any other employee
benefits (other than those specified in the following sentence). Notwithstanding
the foregoing, Concord shall continue to pay Concord's share of the Employee's
health insurance in accordance with Concord's general policies for a period of
six months following any Termination Event.

      (b) "Good Reason" means the occurrence of one or more of the following
events during the term and following a Change in Control:

                  (i) Without the Employee's express written consent, Concord
            shall reduce the Employee's duties and responsibilities from those
            assigned to the Employee immediately prior to the Change in Control;
            or

                  (ii) Without the Employee's express written consent, Concord
            shall require the Employee to have his/her principal location of
            work changed to any location which is in excess of 60 miles from the
            location thereof immediately prior to the Change in Control; or

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                                      -2-

                  (iii) Without the Employee's express written consent, Concord
            shall materially reduce the Employee's benefits under existing
            benefit plans, unless there is a concurrent reduction uniformly
            among all persons entitled to such benefits.

      (c) Effective upon the date immediately following any Change in Control of
Concord, the "Full Vest" date(s) set forth in each of the employee's then
outstanding Notice of Option Grant shall be automatically accelerated by
twenty-four (24) months. Notwithstanding the foregoing, if within twenty-four
(24) months after a Change in Control there is a Termination Event, all of the
Employee's unvested options (but only such options as have been granted to the
Employee by Concord as of the date of the Change in Control or such options as
have been exchanged by the Employee for new options in any acquiring company at
the time of a change in Control) shall automatically become fully vested as of
the date of such Termination Event.

      (d) For purposes of this Agreement, a "Change in Control" shall have
occurred if at any time any of the following events shall occur:

                  (A) Concord is merged, consolidated or reorganized into or
            with another corporation or other legal person, and as a result of
            such merger, consolidation or reorganization less than a majority of
            the combined voting power of the then-outstanding securities of the
            combined corporation or person immediately after such transaction
            are held in the aggregate by the holders of the combined voting
            power of the then-outstanding securities entitled to vote generally
            in the election of directors of Concord ("Voting Stock") immediately
            prior to such transaction;

                  (B) Concord sells or otherwise transfers all or substantially
            all of its assets to any other corporation or other legal person,
            and less than a majority of the combined voting power of the
            then-outstanding securities of such corporation or person
            immediately after such sale or transfer is held in the aggregate by
            the holders of the Voting Stock of concord immediately prior to such
            sale or transfer;

                  (C) There is a report filed on Schedule 13D or Schedule 14D-1
            (or any successor schedule, form or report), each as promulgated
            pursuant to the Exchange Act of 1934 (the "1934 Act"), disclosing
            that any person (as the term "person" is used in Section 13(d)(3) or
            Section 14(d)(2) of the 1934 Act) has become the beneficial owner
            (as the term "beneficial owner" is defined under Rule 13d-3 or any
            successor rule or regulation promulgated under the 1934 Act) of
            securities representing 33% or more of the Voting Stock; or


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                                      -3-

                  (D) Concord files a report or proxy statement with the
            Securities and Exchange Commission pursuant to the 1934 Act
            disclosing in response to Form 8-K or Schedule 14A (or any successor
            schedule, form or report or item therein) that a change in control
            of Concord has or may have occurred or will or may occur in the
            future pursuant to any then-existing contract or transaction.

provided, however, that notwithstanding the foregoing provisions of this Section
1, a "Change in Control" shall not be deemed to have occurred for purposes of
this Agreement solely because (i) Concord, (ii) an entity in which Concord
directly or indirectly beneficially owns 50% or more of the voting securities,
(iii) any Concord sponsored employee stock ownership plan or any other employee
benefit plan of Concord, or (iv) any corporation or legal person approved by the
Board of Directors prior to the occurrence of the event that, absent such
approval by the Board of Directors, would have constituted a Change in Control,
either files or becomes obligated to file a report or a proxy statement under or
in response to Schedule 13D, Schedule 14D-1, Form 8-K or Schedule 14A (or any
successor schedule, form or report or item therein) under the 1934 Act,
disclosing beneficial ownership by it of shares of Voting Stock, whether in
excess of 33% or otherwise, or because Concord reports that a change in control
of Concord has or may have occurred or will or may occur in the future by reason
of such beneficial ownership.

      (e) Notwithstanding anything to the contrary in this Agreement, if the
Employee is a Disqualified Individual (as defined in Section 280G of the
Internal Revenue Code of 1986, as amended (the "Code")) and if any portion of
any acceleration of vesting, payment or transfer of property under this
Agreement would be an Excess Parachute Payment (as defined in Section 280G of
the Code) but for the application of this sentence, then the amount of such
acceleration, payment or transfer otherwise payable to the Employee pursuant to
this Agreement shall be reduced to the minimum extent necessary (but in no event
to less than zero) so that no portion of such payment, as so reduced,
constitutes an Excess Parachute Payment; provided, however, that no reduction
shall be made if the net economic effect would be disadvantageous to the
Employee, taking into account all the facts and circumstances including any tax
savings resulting from the reduction.

      2. Termination, Severance, and Bonus Guarantee. (a) Concord may,
immediately and unilaterally, terminate the Employee's employment with "Cause"
at any time. As used in this Agreement, the term "cause" shall mean:

                  (i) the Employee's willful and substantial misconduct with
            respect to the business and affairs of Concord, or any subsidiary or
            affiliate thereof;

                  (ii) the Employee's gross neglect of duties, dishonesty,
            deliberate disregard of any material rule or policy of Concord or
            the commission by the Employee of any other action with the intent
            to injure Concord, or any subsidiary or affiliate thereof;

                  (iii) the Employee's commission of an act involving
            embezzlement or fraud or commission of a felony; or


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                  (iv) the commission of an act which induces any customer of
            Concord to breach a contract or purchase order with Concord, or any
            subsidiary or affiliate thereof.

            In the event of a termination for "cause" as described herein, the
Employee shall not be entitled to severance or other termination benefits,
including, without limitation, the benefits described in Sections 1 and 2(b) and
2(c) herein.

      (b) If employment is terminated without Cause, Concord will pay severance
in a cash amount equal to twelve months' base annual salary (at the rate being
paid immediately prior to such termination), payable twice a month in accordance
with Concord's normal payroll cycle, upon execution of a full release of all
claims that you may have against Concord, which will be supplied by Concord. The
Employee will not be entitled to continue to receive (i) any other salary or
bonus in the event of a termination for any reason or (ii) any other employee
benefits (other than those specified in the following sentence) in the event of
a termination for any reason. Notwithstanding the foregoing, Concord shall
continue to pay Concord's share of the Employee's health insurance in accordance
with Concord's general policies for a period of twelve (12) months following
termination. Notwithstanding anything contained herein to the contrary, Concord
shall have no obligation to make the salary and health insurance severance
payments described in this subsection (b) after Employee commences employment
following his termination from Concord. Employee is obligated to inform Concord
promptly of such event.

      (c) Employee is guaranteed a minimum, non-recoverable quarterly bonus of
$32,500 for each of the four quarters during the one (1) year beginning on
January 1, 2005, which will be payable to Employee with the last payroll of the
month following the close of each quarter, and only during active employment.
This guaranteed bonus shall not limit the Employee's ability to obtain
additional bonuses under the 2004 and 2005 Executive Bonus Programs, but the
guaranteed bonus provided under this section shall be deducted from amounts
earned thereunder. Any entitlement to this bonus guarantee ceases upon
termination of employment for any reason.

      (d) The Employee's employment shall automatically terminate upon his/her
death and may be terminated by Concord due to him/her disability. If the
Employee dies or his/her employment is terminated due to disability during the
Term, then Employee shall be eligible for such benefits as shall apply to
employees of Concord generally under such circumstances at the time of such
termination.

      As used in this Agreement, the term "disability" shall mean the occurrence
of a mental or physical condition, which renders the Employee incapable of
performing his/her duties for a total of six consecutive months.

      (e) The Employee expressly acknowledges and agrees that, prior to any
Change in Control, Concord may terminate the Employee with or without "Cause" at
any time, subject to the Employee's rights and Concord's obligations specified
in this Agreement. Following any Change in Control, Concord may also terminate
the Employee with or without "cause" at any time subject to the Employee's
rights and Concord's obligations specified in this Agreement.

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                                      -5-

      (f) Concord agrees to make up any portion of Employee's earned 2004
year-end bonus from MRO Software, Inc. that Employee loses as a result of
resignation from MRO Software, Inc. prior to joining Concord. Concord agrees to
pay any such loss within 30 days after the date that such bonuses are paid to
other MRO employees. Employee shall, at the request of Concord, submit such
reasonable documentation as may be required to establish the amount of the bonus
lost, including an affidavit from the Employee.

      3. No Obligation of Employment. Employee understands that the employment
relationship between Employee and Concord will be "at will" and that Concord may
terminate such relationship with or without cause or for any reason or no
reason, subject to the Employee's rights and Concord's obligations specified in
this Agreement.

      4. Noncompetition Agreement. Employee shall execute concurrently herewith
the form of Noncompetition Agreement attached hereto as Exhibit A.

      5. Consent and Waiver by Third Parties. The Employee hereby represents and
warrants that he/she has obtained all waivers and/or consents from third parties
which are necessary to enable him/her to execute and perform this Agreement
without being in conflict with any other agreement, obligation or understanding
with any such third party.

      6. Governing Law. This Agreement shall be governed by and construed in
accordance with the internal laws of the Commonwealth of Massachusetts and this
Agreement shall be deemed to be performable in Massachusetts.

      7. Severability. In case any one or more of the provisions contained in
this Agreement for any reason shall be held to be invalid, illegal or
unenforceable in any respect, such invalidity, illegality or unenforceability
shall not affect any other provision of this Agreement and this Agreement shall
be construed to the maximum extent permitted by law.

      8. Waivers and Modifications. This Agreement may be modified, and the
rights, remedies and obligations contained in any provision hereof may be
waived, only in accordance with this Section 8. No waiver by either party of any
breach by the other or any provision hereof shall be deemed to be a waiver of
any later or other breach thereof or as a waiver of any other provision of this
Agreement. This Agreement sets forth all of the terms of the understandings
between the parties with reference to the subject matter set forth herein and
may not be waived, changed, discharged or terminated orally or by any course of
dealing between the parties, but only by an instrument in writing signed by the
party against whom any waiver, change, discharge or termination is sought.

      9. Assignment. The Employee may not assign any of his/her rights or
delegate any of his/her duties or obligations under this Agreement. The rights
and obligations of Concord under this Agreement shall inure to the benefit of,
and shall be binding upon, the successors and assigns of Concord.

      10. Entire Agreement. This Agreement constitutes the entire understanding
of the parties relating to the subject matter hereof and supersedes and cancels
all agreements, written or

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                                      -6-

oral, made prior to the date hereof between the Employee and Concord relating
to the subject matter hereof; provided, however, that the Employee's existing
option agreements, as modified hereby, shall remain in effect.

      11. Notices. All notices hereunder shall be in writing and shall be
delivered in person or mailed by certified or registered mail, return receipt
requested, addressed as follows:

      If to Concord, to: Concord Communications, Inc.
                         600 Nickerson Road
                         Marlboro, MA 01752
                         Attention: John A. Blaeser

                         With a copy to:
                         Concord Communications, Inc.
                         600 Nickerson Road
                         Marlboro, MA 01752
                         Attention: General Counsel

      If to the Employee, at the Employee's address set forth on the signature
page hereto.

      12. Counterparts. This Agreement may be executed in two or more
counterparts, each of which shall be deemed to be an original, but all of which
together shall constitute one and the same instrument.

      13. Section Headings. The descriptive section headings herein have been
inserted for convenience only and shall not be deemed to define, limit, or
otherwise affect the construction of any provision hereof.

      14. Term. The term of this Agreement (the "Term") shall commence upon the
date hereof and terminate upon the earlier of (i) twenty-four (24) months
following any Change in Control of Concord, (ii) the date prior to any Change in
Control of Concord that the employee for any reason ceases to be an employee of
Concord and (iii) the date following any Change in Control of Concord that the
Employee is terminated for Cause or voluntary terminates his employment (other
than for Good Reason).

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      IN WITNESS WHEREOF, the parties have executed this Agreement as of the day
and year first above written.

                                             CONCORD COMMUNICATIONS, INC.

                                             By: /s/ John A. Blaeser
                                                 ---------------------------
                                                 Name: John A. Blaeser
                                                 Title:President

                                             EMPLOYEE

                                             /s/ Ted D. Williams
                                             -------------------------------
                                             Name: Ted D. Williams
                                             Address: 9 Denton Rd.
                                                      Wellesley, MA 02482

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      Exhibit A

                        EMPLOYEE NONCOMPETITION AGREEMENT

      In consideration and as a condition of my continued employment, I hereby
agree with Concord communications, Inc. ("Concord") as follows:

      1. During the period of my employment by Concord (the "Employment
Period"), I will devote my full working time and best efforts to the business of
Concord. Further, (i) for as long as I am an employee of Concord and (ii) for
the period beginning as of the date of the occurrence of a change in Control
through and including the date to occur which is six months following the date
upon which I am no longer an employee of Concord, I agree that I will not,
directly or indirectly, alone or as a partner, officer, director, employee or
stockholder of any entity (except that I may own not more than 1% of the
outstanding shares of any publicly-traded company), engage in any business
activity which is in competition with the products or services being developed,
manufactured or sold by Concord. The provisions of clause (ii) of the preceding
sentence shall (A) apply only if following a Change in Control my employment
with Concord shall have been terminated (1) without cause or for cause pursuant
to Section 2 of my Management Change in Control Agreement of even date herewith
or (2) for "Good Reason" (as that term is defined in my Management Change in
Control Agreement) and (B) not apply if i shall have voluntarily terminated my
employment with Concord. The period following the termination of my employment
during which the restrictions described above shall apply (the "Post-employment
Period") shall be extended by the length of any period of time during the
Post-employment Period during which I am in violation of this paragraph. Nothing
contained herein shall exclude me from participating in civic, charitable,
religious or non-profit activities so long as such activities do not interfere
with the performance of my duties to Concord.

      2. I agree that any breach of this Agreement by me will cause irreparable
damage to Concord and that in the event of such breach Concord shall have, in
addition to any and all remedies of law, the right to an injunction, specific
performance or other equitable relief to prevent the violation of my obligations
hereunder. I further agree and acknowledge that the post-employment
non-competition provision set forth in Paragraph 1 hereof, and the remedies set
forth in this paragraph, are necessary and reasonable to protect the business of
Concord.

      3. I understand that this Agreement does not create an obligation on
Concord or any other person or entity to continue my employment.

      4. No claim of mine against Concord shall serve as a defense against
Concord's enforcement of any provision of this Agreement.

      5. I hereby represent that I am not a party to, or bound by the terms of,
any agreement with any previous employer, other than Concord, or other party to
refrain from using or disclosing any trade secret or confidential or proprietary
information in the course of my employment with Concord or to refrain from
competing, directly or indirectly, with the business of such previous employer
or any other party, which would prevent me from performing services to or for
Concord in any material way. I further represent that my performance of all the
terms

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of this Agreement and as an employee of Concord does not and will not breach any
agreement to keep in confidence proprietary information, knowledge or data
acquired by me in confidence or in trust prior to my employment with Concord,
and I will not disclose to Concord or induce Concord to use any confidential or
proprietary information or material belonging to any previous employer or
others. I have not entered into, and I agree I will not enter into, any
agreement, either written or oral, in conflict with the terms of this Agreement.

      6. Any waiver by Concord of a breach of any provision of this Agreement
shall not operate or be construed as a waiver of any subsequent breach of such
provision or any other provision hereof.

      7. I hereby agree that each provision herein shall be treated as a
separate and independent clause, and the unenforceability of any one clause
shall in no way impair the enforceability of any of the other clauses herein.
Moreover, if one or more of the provisions contained in this Agreement shall for
any reason be held to be excessively broad as to scope, activity, subject or
otherwise so as to be unenforceable at law, such provision or provisions shall
be construed by the appropriate judicial body by limiting or reducing it or
them, so as to be enforceable to the maximum extent compatible with the
applicable law as it shall then appear.

      8. My obligations under this Agreement shall survive the termination of my
employment regardless of the manner of such termination.

      9. The term "Concord" as used herein shall also include Concord's
subsidiaries, subdivisions or affiliates. Concord shall have the right to assign
this Agreement to its successors and assigns, and all covenants and agreements
hereunder shall inure to the benefit of and be enforceable by said successors or
assigns.

      10. This Agreement shall be governed by and construed in accordance with
the internal laws of the Commonwealth of Massachusetts. Any claims or legal
actions by one party against the other arising out of the relationship between
the parties contemplated herein (whether or not arising under this Agreement)
shall be governed by the laws of the Commonwealth of Massachusetts and shall be
commenced and maintained in any state or federal court located in Massachusetts,
and both parties hereby submit to the jurisdiction and venue of any such court.

      11. Capitalized terms used herein and not otherwise defined shall have the
meanings provided in the Management Change in Control Agreement of even date
herewith.

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      IN WITNESS WHEREOF, the undersigned has executed this Agreement as of the
15th day of October, 2004.

                                                  /s/ Ted D. Williams
                                                  -----------------------------
                                                      Name: Ted D. Williams