delivered the opinion of the Court.
A.C. Rierson appeals from an opinion and order dismissing his original and amended petitions for judicial review of an administrative agency’s decision. The opinion and order was entered by the District Court, First Judicial District, Lewis and Clark County, upon motions to dismiss by the State and the Board of Administration of the Public Employees’ Retirement Division.
Rierson served for over twenty-five years with the Montana Highway Patrol. When Rierson began his career, the patrolmen’s retirement system was administered by the Montana Highway Patrolmen’s Retirement Board. It had interpreted the law to provide for an actuarial equivalent which would increase a patrolman’s pension for additional service after retirement age without drawing on the pension.
In 1971, the function of administering the Highway Patrolmen’s Retirement Act was transferred to the Board of Administration. It interpreted the law differently. Under the new interpretation, no patrolman’s retirement allowance should ever exceed one-half of his final salary, regardless of his years of service. This new interpretation of the retirement statute was applied prospectively.
On September 24, 1973, Rierson wrote to the Board of Administration. Rierson wanted to know how his retirement benefits would be affected if he worked more than twenty-five years with the Highway Patrol. Rierson was told his retirement benefits would not continue to acccumulate after his twenty-fifth year with the Highway Patrol.
On January 30, 1974, Rierson officially requested his regular retirement allowance. Rierson planned to continue as a patrolman, but he made the request because his retirement benefits were fixed and he was no longer working under the retirement program. Initially, Rierson was advised no provision permitted a patrolman to receive retirement benefits while continuing to serve as a *525patrolman. Later, Rierson was told he would be denied additional retirement benefits for his services after twenty-five years.
Rierson resigned from the Highway Patrol on March 8, 1974. Two years later, on April 6, 1976, he requested an administrative hearing on his claim for additional retirement benefits for service after twenty-five years as a patrolman and credit for service in the military.
The administrative hearing was held on July 15, 1976. The Board of Administration denied Rierson’s requested relief on September 16, 1977, and Rierson was notified of the decision ,on December 12, 1977.
On January 11, 1978, Rierson filed a petition for judicial review in Lewis and Clark County. A summons was issued but never served. On May 21, 1979, Rierson filed an amended petition. He returned the original summons and requested an amended summons. Both the amended petition and summons were served on the Board of Administration on May 29, 1979.
On June 18, 1979, the State and the Board of Administration filed motions to dismiss the petition for insufficiency of service of process and failure to state a claim. A hearing on the motion was held on July 3, 1979, and an opinion and order dismissing both the original and amended petitions with prejudice was issued on August 29, 1979. Three grounds were given. First, there was no prompt service of the original petition under section 2-4-702(2)(a), MCA. Consequently, the original petition must be dismissed for lack of District Court jurisdiction. Second, absent such service, the amended petition could not relate back to the original petition under Rule 15(c), M.R.Civ.P. Third, both petitions must be dismissed with prejudice under Rule 41(b), M.R.Civ.P., for lack of prosecution.
The judgment of dismissal was entered on September 25, 1979. Rierson’s notice of appeal was filed on September 28, 1979.
Two issues are raised upon this appeal. The first is whether section 2-4-702(2)(a), MCA, is unconstitutional. The second is whether the District Court erred in granting the motions to dismiss *526Rierson’s petition for judicial review. We uphold the constitutionality of the statute, and we can find no error by the District Court.
Rierson first contends section 2-4-702(2)(a), MCA, is unconstitutionally vague. Next, Rierson implies the statute violates his equal protection rights. Both contentions are without merit.
Section 2-4-702(2)(a), MCA, is not unconstitutionally vague. A statute violates due process for vagueness when the language used does not sufficiently define the required conduct and men of common intelligence must necessarily guess at its meaning. United States v. Powell (1975), 423 U.S. 87, 96 S.Ct. 316, 46 L.Ed.2d 228. Such is not the case with the term “promptly.” “Promptly” is a common word with a plain and well known meaning. That meaning is ready and quick to act, depending on the circumstances. Irvin v. Koehler (2nd Cir. 1916), 230 F. 795; Taft v. Wolma (Tex.Civ.App. 1976), 541 S.W.2d 673. A statute is not unconstitutionally vague merely because clearer and more precise language might have been used. See United States v. Petrillo (1947), 332 U.S. 1, 7, 67 S.Ct. 1538, 1541, 91 L.Ed. 1877, 1882. Moreover, Rierson conceded “promptly” may be governed by standards of reasonableness. Such standards are consonant with due process when they can be judged by a common standard of conduct. See F b Alee Cream Co. v. Arden Farms Co. (S.D.Cal. 1951), 98 F.Supp. 180.
Section 2-4-702(2)(a), MCA, also does not violate Rierson’s equal protection rights. Rierson asserts the statute unconstitutionally discriminates in favor of the government by requiring a stricter standard of service of process simply because Rierson’s claim involves redress against a governmental body. However, this requirement applies with equal force to governmental agencies who seek review of adverse administrative decisions.
We also hold the District Court properly dismissed Reirson’s petition for judicial review for failure of service and lack of prosecution.
The Montana Administrative Procedure Act governs the pro*527cedural aspects of this cause. Under that act, a petition for judicial review must be filed within 30 days after service of the final agency decision, and once filed, the petition must be promptly served upon all parties of record. Section 2-4-702(2)(a), MCA.
Rierson asserts the State and the Board of Administration were timely served under this statute. Rierson first points out that service under the Administrative Procedure Act is governed by the Montana Rules of Civil Procedure unless a statute expressly provides otherwise. Section 2-4-106, MCA. From this Rierson contends “promptly” is an indefinite term, and as a consequence, service is governed by the three-year time limit of Rule 41(e), M.R..Civ.P. Alternatively, Rierson asserts service sixteen and one-half months after filing is prompt. Both contentions are without merit.
When construing a statute words should be given their plain and ordinary meaning. Jones v. Judge (1978), 176 Mont. 251, 577 P.2d 846, 848. As already noted, the plain meaning of “promptly” is ready and quick to act, depending largely on the facts of each cause. Irvin v. Koehler, supra; Taft v. Wolma, supra.
Here, a sixteen and one-half month delay is not reasonable under the facts of this cause. Rierson never served his original petition, and no explanation has been given for this failure. Certainly, service on the State or the Board of Administration could easily have been obtained. Similarly, no acceptable explanation has been given for the delay in filing and serving the amended petition. Rierson’s attorney felt he had three years in which to perfect service of a petition for judicial review. An attorney’s mistake is unfortunate, particularly here where Rierson’s claim was dismissed with prejudice. However, there are two sides to all litigation, and the State and the Board of Administration are entitled to insist on the finality of litigation. Armstrong v. High Crest Oil, Inc. (1974), 164 Mont. 187, 520 P.2d 1081; and State ex rel. Equity Supply Co. v. Dist. Court (1972), 159 Mont. 34, 494 P.2d 911.
Rierson next contends his amended petition should have related back under Rule 15(c), M.R.Civ.P., to the time of his *528original petition which was timely filed but never served. This contention is also without merit.
The amended petition cannot relate back under Rule 15(c), M.R.Civ.P., to the date the original petition was filed. The concept of notice is critical to operation of the relation back rule. In Rozan v. Rosen (1967), 150 Mont. 121, 125, 431 P.2d 870, 872, the relation back rule was described as follows:
“. . . Rule 15(c) is based on the concept that a party who is notified of litigation concerning a given transaction or occurrence has been given all the notice that statutes of limitation are intended to afford. Thus, if the original pleading gives fair notice of the general fact situation out of which the claim or defense arises, an amendment which merely makes more specific what has already been alleged . . . will relate back even though the statute of limitations has run in the interim . . .” (Quoting 3 Moore’s Federal Practice, ¶ 15.15(3) at 15-194 to 15-196.)
Here, the amended petition was filed more than 30 days after Rierson had been served with the final agency decision, and the State and the Board of Administration were never served with the original petition. It follows that the State and the Board of Administration were not given fair notice by the original petition, and the amended petition should be dismissed since the relation back doctrine will not operate.
It is not ordinarily the function of appellate tribunals to review administrative procedures or to establish exact time limits where none has been provided by the legislature. Isobe v. California Unemployment Insurance App. Bd. (1974), 12 Cal.3d 584, 116 Cal. Rptr. 376, 380, 526 P.2d 528, 532. However, for the sake of guidance in the future, we note that service of a petition for judicial review within thirty days, or thereabouts, from the time the petition was filed in the District Court should not result in a dismissal for failure to comply with section 2-4-702(2)(a), MCA.
The opinion and order of the District Court is affirmed. Rierson’s contentions lack substance and Rierson has not carried his burden on appeal.
*529MR. CHIEF JUSTICE HASWELL, and JUSTICES SHEA, concur.