SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 22)*

(Name of Issuer)

(Title of Class of Securities)

(CUSIP Number)

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

(Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box  ¨

NOTE: Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. See Rule 13d-7 for other parties to whom copies are to be sent.

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

Lawrence E. Auriana hereby amends and supplements the Schedule 13D originally filed with the Securities and Exchange Commission (the “SEC”) on August 16, 1991, as amended by Amendment No. 1 filed with the SEC on July 10, 1996, by Amendment No. 2 filed with the SEC on January 6, 2000, by Amendment No. 3 filed with the SEC on January 22, 2001, by Amendment No. 4 filed with the SEC on February 8, 2002, by Amendment No. 5 filed with the SEC on February 7, 2003, by Amendment No. 6 filed with the SEC on July 22, 2003, by Amendment No. 7 filed with the SEC on November 7, 2003, by Amendment No. 8 filed with the SEC on February 6, 2004, by Amendment No. 9 filed with the SEC on May 6, 2004, by Amendment No. 10 filed with the SEC on December 9, 2004, by Amendment No. 11 filed with the SEC on October 7, 2005, by Amendment No. 12 filed with the SEC on June 12, 2006, by Amendment No. 13 filed with the SEC on March 5, 2008, by Amendment No. 14 filed with the SEC on March 23, 2009, by Amendment No. 15 filed with the SEC on August 4, 2009, by Amendment No. 16 filed with the SEC on January 12, 2010, by Amendment No. 17 filed with the SEC on July 9, 2010, by Amendment No. 18 filed with the SEC on January 7, 2011, by Amendment No. 19 filed with the SEC on July 1, 2011, by Amendment No. 20 filed with the SEC on January 10, 2012 and as further amended by Amendment No. 21 filed with the SEC on February 15, 2012 (the “Schedule”) as follows:

This Schedule relates to the common stock, par value $.10 per share (“Common Stock”), of Mediware Information Systems, Inc., a New York corporation (the “Company”).

Item 6. Contracts, Arrangements, Understandings or Relationships With Respect to Securities of the Issuer.

Item 6 of the Schedule is hereby supplemented by inserting the following text as the last paragraph thereof:

“On September 11, 2012, the Company announced that it had entered into an Agreement and Plan of Merger (the “Merger Agreement”) with Project Ruby Parent Corp., a Delaware corporation (“Parent”) and Project Ruby Merger Corp., a New York corporation and a wholly owned subsidiary of Parent (“Merger Subsidiary”), providing for the merger (“Merger”) of Merger Subsidiary with and into the Company, with the Company surviving the Merger as a wholly-owned subsidiary of Parent. Parent and Merger Subsidiary are controlled affiliates of Thoma Bravo, LLC.

In connection with the execution of the Merger Agreement, Mr. Auriana entered into a Voting Agreement, dated the date of the Merger Agreement, with Parent (the “Voting Agreement”), pursuant to which, among other things, Mr. Auriana agreed, subject to the terms and conditions set forth therein, to vote his shares of Common Stock in favor of the Merger Agreement and the transactions contemplated thereby. The foregoing summary of the Voting Agreement does not purport to be complete and is qualified in its entirety by the Voting Agreement, which is attached hereto as Exhibit 1 and incorporated herein by reference.”

Item 7. Material To Be Filed As Exhibits.

Item 7 of the Schedule is hereby amended by adding the following Exhibit:

“Exhibit 1 Voting Agreement, dated as of September 11, 2012, by and between Project Ruby Parent Corp. and Lawrence Auriana.”

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: September 14, 2012

EXHIBIT INDEX

Exhibit 1

VOTING AGREEMENT

THIS VOTING AGREEMENT (this “Agreement”) is made and entered into as of September 11, 2012 by and between Project Ruby Parent Corp., a Delaware corporation (“Parent”), and the undersigned stockholder (“Holder”) of Mediware Information Systems, Inc., a New York corporation (the “Company”).

RECITALS

Pursuant to an Agreement and Plan of Merger, dated as of the date hereof (the “Merger Agreement”), by and among Parent, Project Ruby Merger Corp., a New York corporation and wholly-owned subsidiary of Parent (“Merger Sub”), and the Company, Merger Sub is merging with and into the Company (the “Merger”) and the Company, as the surviving corporation of the Merger, will thereby become a wholly-owned subsidiary of Parent. Concurrently with the execution and delivery of the Merger Agreement and as a condition and inducement to Parent and Merger Sub to enter into the Merger Agreement, Parent has required that Holder enter into this Agreement. Holder is the beneficial owner (within the meaning of Rule 13d-3 of the Exchange Act) of such number of shares of the outstanding Common Stock, par value $0.01 per share, of the Company as is indicated beneath Holder’s signature on the last page of this Agreement (the “Shares”). Capitalized terms used herein but not defined shall have the meanings ascribed to them in the Merger Agreement.

AGREEMENT

The parties agree as follows:

1. Agreement to Retain Shares.

(a) Transfer. During the period beginning on the date hereof and ending on the earlier to occur of (i) the Effective Time and (ii) the Expiration Date (as defined in Section 4 below), (1) except as contemplated by the Merger Agreement, and except as provided in Section 1(b) below, Holder agrees not to, directly or indirectly, sell, transfer, exchange or otherwise dispose of (including by merger, consolidation or otherwise by operation of law) the Shares or any New Shares (as defined below), and (2) Holder agrees not to, directly or indirectly, grant any proxies or powers of attorney, deposit any of such Holder’s Shares into a voting trust or enter into a voting agreement with respect to any of such Holder’s Shares, or enter into any agreement or arrangement providing for any of the actions described in this clause (2).

(b) Permitted Transfers. Section 1(a) shall not prohibit a transfer of Shares or New Shares (as defined below) by Holder to (i) any family member or trust for the benefit of any family member, (ii) any stockholder, member or partner of any Holder which is an entity or (iii) any Affiliate of such Holder, so long as, in any such case, the assignee or transferee agrees to be bound by the terms of this Agreement and executes and delivers to the parties hereto a written consent memorializing such agreement.

(c) New Shares. Holder agrees that any shares of Company Common Stock that Holder purchases or with respect to which Holder otherwise acquires record or beneficial ownership (but excluding shares of Company Common Stock underlying unexercised Company Options (until such time as any such Company Options are exercised and the underlying shares of Company Common Stock are acquired by the Holder)) after the date of this Agreement and prior to the earlier to occur of (i) the Effective Time and (ii) the Expiration Date (“New Shares”) shall be subject to the terms and conditions of this Agreement to the same extent as if they constituted Shares.

2. Agreement to Vote Shares.

(a) Until the earlier to occur of the Effective Time and the Expiration Date, at every meeting of the stockholders of the Company called with respect to any of the following, and at every adjournment thereof, and on every action or approval by written consent of the stockholders of the Company with respect to any of the following, Holder shall appear at such meeting (in person or by proxy) and shall vote or consent the Shares and any New Shares (i) in favor of adoption of the Merger Agreement and the approval of the transactions contemplated thereby and (ii) against any Acquisition Proposal by a Third Party (the “Covered Proposals”). This Agreement is intended to bind Holder as a stockholder of the Company only with respect to the Covered Proposals. Except as expressly set forth in clauses (i) and (ii) of this Section 2, Holder shall not be restricted from voting in favor of, against or abstaining with respect to any other matter presented to the stockholders of the Company. Until the earlier to occur of the Effective Time and the Expiration Date, Holder covenants and agrees not to enter into any agreement or understanding with any person with respect to voting of its Shares on any Covered Proposal which conflicts with the terms of this Agreement.

(b) Holder further agrees that, until the earlier to occur of the Effective Time and the Expiration Date, Holder will not, and will not permit any entity under Holder’s control to, (A) solicit proxies or become a “participant” in a “solicitation” (as such terms are defined in Rule 14A under the Exchange Act) in opposition to any Covered Proposal, (B) initiate a stockholders’ vote with respect to an Acquisition Proposal of a Third Party or (C) become a member of a “group” (as such term is used in Section 13(d) of the Exchange Act) with respect to any voting securities of the Company with respect to an Acquisition Proposal of a Third Party.

(c) Subject to the provisions set forth in Section 5 hereof, and as security for Holder’s obligations under Section 2(a), Holder hereby irrevocably constitutes and appoints Parent and its designees as his attorney and proxy in accordance with the General Corporation Law of the State of New York, with full power of substitution and resubstitution, to cause the Shares to be counted as present at the Shareholders’ Meeting, to vote his Shares at the Shareholders’ Meeting, however called, and to execute consents in respect of his Shares with respect to the Covered Proposals. SUBJECT TO THE PROVISIONS SET FORTH IN SECTION 5 HEREOF, THIS PROXY AND POWER OF ATTORNEY IS IRREVOCABLE AND COUPLED WITH AN INTEREST. Upon the execution of this Agreement, Holder hereby revokes any and all prior proxies or powers of attorney given by Holder with respect to voting of the Shares on the Covered Proposals and agrees not to grant any subsequent proxies or powers of attorney with respect to the voting of the Shares on any Covered Proposal until after the Expiration Date. Holder understands and acknowledges that Parent is entering into the Merger Agreement in reliance upon the Holder’s execution and delivery of this Agreement and Holder’s granting of the proxy contained in this Section 2(c). Holder hereby affirms that the proxy granted in this Section 2(c) is given in connection with the execution of the Merger Agreement, and that such proxy is given to secure the performance of the duties of Holder under this Agreement.

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3. Representations, Warranties and Covenants of Holder. Holder hereby represents, warrants and covenants to Parent that Holder (i) is the beneficial owner of the Shares, which, at the date of this Agreement and at all times up until the earlier to occur of (A) the Effective Time and (B) the Expiration Date, will be free and clear of any liens, claims, options, charges or other encumbrances (other than those created by this Agreement) and (ii) as of the date hereof does not own of record or beneficially any shares of capital stock of the Company other than the Shares (excluding shares as to which Holder currently disclaims beneficial ownership in accordance with applicable law). Holder has the legal capacity, power and authority to enter into and perform all of Holder’s obligations under this Agreement (including under the proxy granted in Section 2(c) above). This Agreement (including the proxy granted in Section 2(c) above) has been duly and validly executed and delivered by Holder and constitutes a valid and binding agreement of Holder, enforceable against Holder in accordance with its terms, subject to (a) laws of general application relating to bankruptcy, insolvency and the relief of debtors and (b) rules of law governing specific performance, injunctive relief and other equitable remedies.

4. Termination. This Agreement and the proxy delivered in connection herewith shall terminate and shall have no further force and effect as of the earliest to occur of (i) the date of termination of the Merger Agreement in accordance with the terms and provisions thereof, (ii) the date that Parent notifies the Company that it is not willing or not able to proceed with the Merger on substantially the terms set forth in the Merger Agreement, including by advising the Company that it is unwilling to proceed with the Merger unless the Merger Consideration is reduced (this clause (ii) shall not be deemed any admission that Parent has the right to do so except pursuant to the terms of the Merger Agreement), (iii) the date following the date of the Stockholders’ Meeting, including any adjournment or postponement thereof and (iv) the Outside Date (the earliest of such dates, the “Expiration Date”).

5. Fiduciary Duties. Notwithstanding anything in this Agreement to the contrary: (i) Holder makes no agreement or understanding herein in any capacity other than in Holder’s capacity as a beneficial owner of the Shares, (ii) nothing in this Agreement shall be construed to limit or affect the Holder’s rights and obligations as a director, officer, or other fiduciary of the Company, and (iii) Holder shall have no liability to Parent, Merger Sub or any of their Affiliates under this Agreement as a result of any action or inaction by Holder acting in his capacity as a director, officer, or other fiduciary of the Company.

6. Miscellaneous.

(a) Amendments and Waivers. Any term of this Agreement may be amended or waived with the written consent of the parties or their respective successors and assigns. Any amendment or waiver effected in accordance with this Section 6(a) shall be binding upon the parties and their respective successors and assigns.

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(b) Governing Law; Venue. This Agreement shall be governed by and construed in accordance with the laws of the State of New York, without giving effect to principles of conflicts of law thereof. Each of the parties hereto (i) consents to submit to the personal jurisdiction of any federal court located in the State of New York or any New York state court in the event any dispute arises out of this Agreement, (ii) agrees that it shall not attempt to deny or defeat such personal jurisdiction by motion or other request for leave from any such court and (iii) agrees that it shall not bring any action relating to this Agreement in any court other than a federal or state court sitting in the State of New York.

(c) Counterparts. This Agreement may be executed in two or more counterparts, each of which shall be deemed an original and all of which together shall constitute one instrument.

(d) Titles and Subtitles. The titles and subtitles used in this Agreement are used for convenience only and are not to be considered in construing or interpreting this Agreement.

(e) Notices. Any notice required or permitted by this Agreement shall be in writing and shall be deemed sufficient upon receipt, when delivered personally or by courier, overnight delivery service or confirmed facsimile, or 72 hours after being deposited in the regular mail as certified or registered mail with postage prepaid, if such notice is addressed to the party to be notified at such party’s address or facsimile number as set forth below, or as subsequently modified by written notice.

(f) Severability. If one or more provisions of this Agreement are held to be unenforceable under applicable law, the parties agree to renegotiate such provision in good faith, in order to maintain the economic position enjoyed by each party as close as possible to that under the provision rendered unenforceable. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such provision, then (i) such provision shall be excluded from this Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in accordance with its terms.

(g) Specific Performance. Each of the parties hereto recognizes and acknowledges that a breach of any covenants or agreements contained in this Agreement will cause Parent and Merger Sub to sustain damages for which they would not have an adequate remedy at law for money damages, and therefore each of the parties hereto agrees that in the event of any such breach Parent shall be entitled to the remedy of specific performance of such covenants and agreements and injunctive and other equitable relief in addition to any other remedy to which they may be entitled, at law or in equity.

[SIGNATURE PAGE FOLLOWS]

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IN WITNESS WHEREOF, the parties have caused this Voting Agreement to be duly executed on the date first above written.

[Signature Page to Voting Agreement]

Shares of Common

Stock: 2,432,525

[Signature Page to Voting Agreement]